World Trade Center
|World Trade Center|
The original World Trade Center of New York City in March 2001. The red granite-clad building left of the Twin Towers is the original 7 World Trade Center. The North Tower (left), with antenna spire, is 1 WTC. The South Tower (right) is 2 WTC. All 7 buildings are partially visible (see map below). Background shows the East River.
|Tallest in the world from 1971 to 1973[I]|
|Preceded by||Empire State Building|
|Surpassed by||Sears Tower|
|Location||New York City|
|Groundbreaking||August 25, 1966|
|Opening||April 4, 1973|
|Destroyed||September 11, 2001|
|Antenna spire||1 WTC: 1,727 ft (526.3 m)|
|Lifts/elevators||Both had 99 elevators|
|Design and construction|
|Owner||Port Authority of New York and New Jersey|
|Engineer||Leslie E. Robertson Associates|
The World Trade Center is a complex of buildings under construction in Lower Manhattan, New York City, United States, replacing an earlier complex of seven buildings with the same name on the same site. The original World Trade Center featured landmark twin towers, which opened on April 4, 1973 and were destroyed in the September 11 attacks of 2001, along with 7 World Trade Center. The other buildings in the complex were damaged in the attacks, and their ruins were eventually demolished. The site is being rebuilt with five new skyscrapers and a memorial to those killed in the attacks. As of November 2011[update], only one skyscraper has been completed; the other four are expected to be completed before 2020. One World Trade Center will be the lead building for the new complex, reaching more than 100 stories at its completion. It became the tallest building in New York City on April 30, 2012, and is expected to be finished by 2013. A sixth tower is awaiting confirmation.
At the time of their completion, the original 1 World Trade Center (the North Tower) and 2 World Trade Center (the South Tower), known collectively as the "Twin Towers", were the tallest buildings in the world. The other buildings included 3 WTC (the Marriott World Trade Center), 4 WTC, 5 WTC, 6 WTC, and 7 WTC. All of these buildings were built between 1975 and 1985. The cost for the construction was $400 million ($2,300,000,000 in 2013 dollars). The complex was located in the heart of New York City's downtown financial district and contained 13.4 million square feet (1.24 million m2) of office space.
The World Trade Center experienced a fire on February 13, 1975, a bombing on February 26, 1993 and a robbery on January 14, 1998. In 1998, the Port Authority decided to privatize the World Trade Center, leasing the buildings to a private company to manage, and awarded the lease to Silverstein Properties in July 2001.
On the morning of September 11, 2001, Al-Qaeda-affiliated hijackers flew two Boeing 767 jets into the complex, one into each tower, in a coordinated terrorist attack. After burning for 56 minutes, the South Tower (2) collapsed, followed a half-hour later by the North Tower (1), with the attacks on the World Trade Center resulting in 2,753 deaths. Falling debris from the towers, combined with fires that the debris initiated in several surrounding buildings, led to the partial or complete collapse of all the other buildings in the complex and caused catastrophic damage to ten other large structures in the surrounding area. The process of cleanup and recovery at the World Trade Center site took eight months.
Over the following years, plans for a rebuilt World Trade Center took form. The first new building at the site was 7 World Trade Center, which opened in May 2006. The Lower Manhattan Development Corporation (LMDC), established in November 2001 to oversee the rebuilding process, organized competitions to select a site plan and memorial design. Memory Foundations, designed by Daniel Libeskind, was selected as the master plan, but this went through substantial changes in design. The new World Trade Center complex will include One World Trade Center, three other high-rise office towers, and the National September 11 Memorial & Museum.
Planning and construction
The idea of establishing a World Trade Center in New York City was first proposed in 1943. The New York State Legislature passed a bill authorizing New York Governor Thomas E. Dewey to begin developing plans for the project but the plans were put on hold in 1949. During the late 1940s and 1950s, economic growth in New York City was concentrated in Midtown Manhattan. To help stimulate urban renewal in Lower Manhattan, David Rockefeller suggested that the Port Authority build a World Trade Center in Lower Manhattan.
Initial plans, made public in 1961, identified a site along the East River for the World Trade Center. As a bi-state agency, the Port Authority required approval for new projects from the governors of both New York and New Jersey. New Jersey Governor Robert B. Meyner objected to New York getting a $335 million project. Toward the end of 1961, negotiations with outgoing New Jersey Governor Meyner reached a stalemate.
At the time, ridership on New Jersey's Hudson and Manhattan Railroad (H&M) had declined substantially from a high of 113 million riders in 1927 to 26 million in 1958 after new automobile tunnels and bridges had opened across the Hudson River. In a December 1961 meeting between Port Authority director Austin J. Tobin and newly elected New Jersey Governor Richard J. Hughes, the Port Authority offered to take over the Hudson & Manhattan Railroad to have it become the Port Authority Trans-Hudson (PATH). The Port Authority also decided to move the World Trade Center project to the Hudson Terminal building site on the west side of Lower Manhattan, a more convenient location for New Jersey commuters arriving via PATH. With the new location and Port Authority acquisition of the H&M Railroad, New Jersey, agreed to support the World Trade Center project.
Approval was also needed from New York City Mayor John Lindsay and the New York City Council. Disagreements with the city centered on tax issues. On August 3, 1966, an agreement was reached that the Port Authority would make annual payments to the City in lieu of taxes for the portion of the World Trade Center leased to private tenants. In subsequent years, the payments would rise as the real estate tax rate increased.
On September 20, 1962, the Port Authority announced the selection of Minoru Yamasaki as lead architect and Emery Roth & Sons as associate architects. Yamasaki devised the plan to incorporate twin towers; Yamasaki's original plan called for the towers to be 80 stories tall, but to meet the Port Authority's requirement for 10,000,000 square feet (930,000 m2) of office space, the buildings would each have to be 110 stories tall.
A major limiting factor in building height is the issue of elevators; the taller the building, the more elevators are needed to service the building, requiring more space-consuming elevator banks. Yamasaki and the engineers decided to use a new system with two "sky lobbies"—floors where people could switch from a large-capacity express elevator to a local elevator that goes to each floor in a section. This system, inspired by the New York City Subway system, allowed the design to stack local elevators within the same elevator shaft. Located on the 44th and 78th floors of each tower, the sky lobbies enabled the elevators to be used efficiently, increasing the amount of usable space on each floor from 62 to 75 percent by reducing the number of elevator shafts. Altogether, the World Trade Center had 95 express and local elevators.
Yamasaki's design for the World Trade Center, unveiled to the public on January 18, 1964, called for a square plan approximately 208 feet (63 m) in dimension on each side. The buildings were designed with narrow office windows 18 inches (46 cm) wide, which reflected Yamasaki's fear of heights as well as his desire to make building occupants feel secure. Yamasaki's design included building facades sheathed in aluminum-alloy. The World Trade Center was one of the most-striking American implementations of the architectural ethic of Le Corbusier, and it was the seminal expression of Yamasaki's gothic modernist tendencies.
In addition to the twin towers, the plan for the World Trade Center complex included four other low-rise buildings, which were built in the early 1970s. The 47-story 7 World Trade Center building was added in the 1980s, to the north of the main complex. Altogether, the main World Trade Center complex occupied a 16-acre (65,000 m2) superblock.
The structural engineering firm Worthington, Skilling, Helle & Jackson worked to implement Yamasaki's design, developing the tube-frame structural system used in the twin towers. The Port Authority's Engineering Department served as foundation engineers, Joseph R. Loring & Associates as electrical engineers, and Jaros, Baum & Bolles as mechanical engineers. Tishman Realty & Construction Company was the general contractor on the World Trade Center project. Guy F. Tozzoli, director of the World Trade Department at the Port Authority, and Rino M. Monti, the Port Authority's Chief Engineer, oversaw the project. As an interstate agency, the Port Authority was not subject to local laws and regulations of the City of New York including building codes. Nonetheless, the structural engineers of the World Trade Center ended up following draft versions of the new 1968 building codes. The tube-frame design, earlier introduced by Fazlur Khan, was a new approach that allowed more open floor plans than the traditional design that distributed columns throughout the interior to support building loads. The World Trade Center towers used high-strength, load-bearing perimeter steel columns called Vierendeel trusses that were spaced closely together to form a strong, rigid wall structure, supporting virtually all lateral loads such as wind loads, and sharing the gravity load with the core columns. The perimeter structure containing 59 columns per side was constructed with extensive use of prefabricated modular pieces each consisting of three columns, three stories tall, connected by spandrel plates. The spandrel plates were welded to the columns to create the modular pieces off-site at the fabrication shop. Adjacent modules were bolted together with the splices occurring at mid-span of the columns and spandrels. The spandrel plates were located at each floor, transmitting shear stress between columns, allowing them to work together in resisting lateral loads. The joints between modules were staggered vertically so the column splices between adjacent modules were not at the same floor.
The core of the towers housed the elevator and utility shafts, restrooms, three stairwells, and other support spaces. The core of each tower was a rectangular area 87 by 135 feet (27 by 41 m) and contained 47 steel columns running from the bedrock to the top of the tower. The large, column-free space between the perimeter and core was bridged by prefabricated floor trusses. The floors supported their own weight as well as live loads, providing lateral stability to the exterior walls and distributing wind loads among the exterior walls. The floors consisted of 4 inches (10 cm) thick lightweight concrete slabs laid on a fluted steel deck. A grid of lightweight bridging trusses and main trusses supported the floors. The trusses connected to the perimeter at alternate columns and were on 6 foot 8 inch (2.03 m) centers. The top chords of the trusses were bolted to seats welded to the spandrels on the exterior side and a channel welded to the core columns on the interior side. The floors were connected to the perimeter spandrel plates with viscoelastic dampers that helped reduce the amount of sway felt by building occupants.
Hat trusses (or "outrigger truss") located from the 107th floor to the top of the buildings were designed to support a tall communication antenna on top of each building. Only 1 WTC (north tower) actually had an antenna fitted; it was added in 1978. The truss system consisted of six trusses along the long axis of the core and four along the short axis. This truss system allowed some load redistribution between the perimeter and core columns and supported the transmission tower.
The tube frame design using steel core and perimeter columns protected with sprayed-on fire resistant material created a relatively lightweight structure that would sway more in response to the wind compared to traditional structures such as the Empire State Building that have thick, heavy masonry for fireproofing of steel structural elements. During the design process, wind tunnel tests were done to establish design wind pressures that the World Trade Center towers could be subjected to and structural response to those forces. Experiments also were done to evaluate how much sway occupants could comfortably tolerate, however, many subjects experienced dizziness and other ill effects. One of the chief engineers Leslie Robertson worked with Canadian engineer Alan G. Davenport to develop viscoelastic dampers to absorb some of the sway. These viscoelastic dampers, used throughout the structures at the joints between floor trusses and perimeter columns along with some other structural modifications, reduced the building sway to an acceptable level.
In March 1965, the Port Authority began acquiring property at the World Trade Center site. Demolition work began on March 21, 1966, to clear thirteen square blocks of low rise buildings in Radio Row for construction of the World Trade Center. Groundbreaking for the construction of the World Trade Center took place on August 5, 1966.
The site of the World Trade Center was located on landfill with the bedrock located 65 feet (20 m) below. To construct the World Trade Center, it was necessary to build a "bathtub" with a slurry wall around the West Street side of the site, to keep water from the Hudson River out. The slurry method selected by Port Authority's chief engineer, John M. Kyle, Jr., involved digging a trench, and as excavation proceeded, filling the space with a "slurry" mixture composed of bentonite and water, which plugged holes and kept groundwater out. When the trench was dug out, a steel cage was inserted and concrete was poured in, forcing the "slurry" out. It took fourteen months for the slurry wall to be completed; it was necessary before excavation of material from the interior of the site could begin. The 1.2 million cubic yards (917,000 m3) of material excavated were used (along with other fill and dredge material) to expand the Manhattan shoreline across West Street to form Battery Park City.
In January 1967, the Port Authority awarded $74 million in contracts to various steel suppliers, and Karl Koch was hired to erect the steel. Tishman Realty & Construction was hired in February 1967 to oversee construction of the project. Construction work began on the North Tower in August 1968; construction on the South Tower was underway by January 1969. The original Hudson Tubes, carrying PATH trains into Hudson Terminal, remained in service as elevated tunnels during the construction process until 1971 when a new PATH station opened.
The topping out ceremony of 1 WTC (North Tower) took place on December 23, 1970, while 2 WTC's ceremony (South Tower) occurred later on July 19, 1971. The first tenants moved into the North Tower in December 1970; the South Tower accepted tenants in January 1972. When the World Trade Center twin towers were completed, the total costs to the Port Authority had reached $900 million. The ribbon cutting ceremony was on April 4, 1973.
Plans to build the World Trade Center were controversial. The site for the World Trade Center was the location of Radio Row, home to hundreds of commercial and industrial tenants, property owners, small businesses, and approximately 100 residents, many of whom fiercely resisted forced relocation. A group of small businesses affected filed an injunction challenging the Port Authority's power of eminent domain. The case made its way through the court system to the United States Supreme Court; the Court refused to accept the case.
Private real estate developers and members of the Real Estate Board of New York, led by Empire State Building owner Lawrence A. Wien, expressed concerns about this much "subsidized" office space going on the open market, competing with the private sector when there was already a glut of vacancies. The World Trade Center itself wasn't rented out completely until after 1979. Others questioned whether the Port Authority really ought to take on a project described by some as a "mistaken social priority".
The World Trade Center design brought criticism of its aesthetics from the American Institute of Architects and other groups. Lewis Mumford, author of The City in History and other works on urban planning, criticized the project and described it and other new skyscrapers as "just glass-and-metal filing cabinets". The twin towers' narrow office windows, only 18 inches (46 cm) wide and framed by pillars that restricted views on each side to narrow slots, were disliked by many. Activist and sociologist Jane Jacobs also criticized plans for the WTC's construction, arguing that the waterfront should be kept open for New Yorkers to enjoy.
The trade center's "superblock", replacing a more traditional, dense neighborhood, was regarded by some critics as an inhospitable environment that disrupted the complicated traffic network typical of Manhattan. For example, in his book The Pentagon of Power, Lewis Mumford denounced the center as an "example of the purposeless giantism and technological exhibitionism that are now eviscerating the living tissue of every great city".
For many years, the immense Austin J. Tobin Plaza was often beset by brisk winds at ground level. In fact, some gusts were so high that pedestrian travel had to be aided by ropes. In 1999, the outdoor plaza reopened after undergoing $12 million renovations, which involved replacing marble pavers with gray and pink granite stones, adding new benches, planters, new restaurants, food kiosks and outdoor dining areas.
North and South towers
With the construction of 7 World Trade Center in the 1980s, the World Trade Center had a total of seven buildings, but the most notable were the main two towers. Each stood over 1,350 feet (410 m) high, and occupied about one acre (43,560 square feet) of the total 16 acres (65,000 m2) of the site's land. During a press conference in 1973, Yamasaki was asked, "Why two 110-story buildings? Why not one 220-story building?" His response was: "I didn't want to lose the human scale."
When completed in 1972, 1 World Trade Center (the North Tower) became the tallest building in the world for two years, surpassing the Empire State Building after a 40-year reign. The North Tower stood 1,368 feet (417 m) tall and featured a telecommunications antenna or mast that was added at the top of the roof in 1978 and stood 360 feet (110 m) tall. With the 360-foot (110 m)-tall antenna/mast, the highest point of the North Tower reached 1,728 ft (527 m). 2 World Trade Center (the South Tower) became the second tallest building in the world when completed in 1973. The South Tower's rooftop observation deck was 1,362 ft (415 m) high and its indoor observation deck was 1,310 ft (400 m) high. The World Trade Center towers held the height record only briefly: Chicago's Sears Tower, finished in May 1973, reached 1,450 feet (440 m) at the rooftop. Throughout their existence, however, the WTC towers had more floors (at 110) than any other building. This number was not surpassed until the advent of the Burj Khalifa, which opened in 2010.
Of the 110 stories, eight were set aside for technical services in mechanical floors Level B5/B6 (floors 7/8, 41/42, 75/76, and 108/109), which are four two-floor areas that evenly spaced up the building. All the remaining floors were free for open-plan offices. Each floor of the towers had 40,000 square feet (3,700 m2) of space for occupancy. Each tower had 3,800,000 square feet (350,000 m2) of office space. Altogether the entire complex of seven buildings had 11,200,000 square feet (1,040,000 m2) of space.
Initially conceived as a complex dedicated to companies and organizations directly taking part in "world trade", they at first failed to attract the expected clientele. During the early years, various governmental organizations became key tenants of the World Trade Center including the State of New York. It was not until the 1980s that the city's perilous financial state eased, after which an increasing number of private companies—mostly financial firms tied to Wall Street—became tenants. During the 1990s, approximately 500 companies had offices in the complex including many financial companies such as Morgan Stanley, Aon Corporation, Salomon Brothers and the Port Authority itself. The basement concourse of the World Trade Center included The Mall at the World Trade Center, along with a PATH station. The North Tower became the home of the corporate headquarters of Cantor Fitzgerald, and it also became the headquarters of the Port Authority of New York and New Jersey.
Electrical service to the towers was supplied by Consolidated Edison (ConEd) at 13,800 volts. This service passed through the World Trade Center Primary Distribution Center (PDC) and sent up through the core of the building to electrical substations located on the mechanical floors. The substations stepped down the 13,800 primary voltage to 480/277 volt secondary service, and then further down to 208/120 volt general power and lighting service. The complex also was served by emergency generators located in the sub-levels of the towers and on the roof of 5 WTC.
The 110th floor of 1 World Trade Center (the North Tower) housed radio and television transmission equipment. The roof of 1 WTC contained a vast array of transmission antennas including the 360 ft (approx 110 m) center antenna mast, rebuilt in 1999 by Dielectric Inc. to accommodate DTV. The center mast contained the television signals for almost all NYC television broadcasters: WCBS-TV 2, WNBC-TV 4, WNYW 5, WABC-TV 7, WPIX 11, WNET 13 Newark, WPXN-TV 31 and WNJU 47 Linden. It also had four NYC FM broadcasters: WPAT-FM 93.1, WNYC 93.9, WKCR 89.9, and WKTU 103.5. Access to the roof was controlled from the WTC Operations Control Center (OCC) located in the B1 level of 2 WTC.
Top of the World observation deck
Although most of the space in the World Trade Center complex was off-limits to the public, the South Tower featured an indoor and outdoor public observation area called Top of the World Trade Center Observatories on its 107th and 110th floors. Visitors would pass through security checks added after the 1993 World Trade Center bombing, then were whisked to the 107th floor indoor observatory at a height of 1,310 feet (400 m). The columns on each face of the building were narrowed on this level to allow 28 inches of glass between them. The Port Authority renovated the observatory in 1995, then leased it to Ogden Entertainment to operate. Attractions added to the observation deck included a simulated helicopter ride around the city. The 107th floor food court was designed with a subway car theme and featured Sbarro and Nathan's Famous Hot Dogs. Weather permitting, visitors could take two short escalator rides up from the 107th floor viewing area to an outdoor viewing platform on the 110th floor at a height of 1,377 ft (420 m). On a clear day, visitors could see up to 50 miles (80 km). An anti-suicide fence was placed on the roof itself, with the viewing platform set back and elevated above it, requiring only an ordinary railing and leaving the view unobstructed, unlike the observation deck of the Empire State Building.
Windows on the World restaurant
The North Tower had a restaurant on its 106th and 107th floors called Windows on the World, which opened in April 1976. The restaurant was developed by Joe Baum at a cost of more than $17 million. Aside from the main restaurant, two offshoots were located at the top of the North Tower: "Hors d'Oeuvrerie" (offered a Danish smorgasbord during the day and sushi in the evening) and "Cellar in the Sky" (a small wine bar). Windows on the World also had a wine school program run by Kevin Zraly. Windows on the World was closed following the 1993 World Trade Center bombing. Upon reopening in 1996, Hors d'Oeuvrerie and Cellar in the Sky were replaced with the "Greatest Bar on Earth" and "Wild Blue". In 2000, its last full year of operation, Windows on the World reported revenues of $37 million, making it the highest-grossing restaurant in the United States. The Skydive Restaurant, opened in 1976 on the 44th floor of the North Tower, was also operated by Windows on the World restaurant, but served only lunch.
Five smaller buildings stood around the 16 acres (65,000 m2) block. One was the 22-floor hotel, which opened in 1981 as the Vista Hotel, and in 1995 became the Marriott World Trade Center (3 WTC) at the southwest corner of the site. Three low-rise buildings (4 WTC, 5 WTC, and 6 WTC) in the same hollow tube design as the towers also stood around the plaza. 6 World Trade Center, at the northwest corner, housed the United States Customs Service and the U.S. Commodities Exchange. 5 World Trade Center was located at the northeast corner above the PATH station and 4 World Trade Center was at the southeast corner. In 1987, a 47-floor office building called 7 World Trade Center was built north of the block. Beneath the World Trade Center complex was an underground shopping mall, which in turn had connections to various mass transit facilities including the New York City Subway system and the Port Authority's own PATH trains connecting Manhattan to Jersey City, Hoboken, and Newark.
One of the world's largest gold depositories was stored underneath the World Trade Center, owned by a group of commercial banks. The 1993 bomb detonated close by the vault held. Seven weeks after the September 11 attacks, $230 million in precious metals was removed from basement vaults of 4 WTC, which included 3,800 100-Troy-ounce registered gold bars and 30,000 1,000-ounce silver bars.
Life and events
On a typical weekday 50,000 people worked in the towers with another 200,000 passing through as visitors. The complex was so large that it had its own zip code: 10048. The towers offered expansive views from the observation deck atop the South Tower and the Windows on the World restaurant on top of the North Tower. The Twin Towers became known worldwide, appearing in numerous movies and television shows as well as on postcards and other merchandise, and became seen as a New York icon, in the same league as the Empire State Building, Chrysler Building and the Statue of Liberty.
Brooklyn toymaker George Willig scaled the exterior of the south tower in 1977. In 1983, on Memorial Day, high-rise firefighting and rescue advocate Dan Goodwin successfully climbed the outside of the WTC's North Tower. His stunt was meant to call attention to the inability to rescue people potentially trapped in the upper floors of skyscrapers.
February 13, 1975 fire
On February 13, 1975, a three-alarm fire broke out on the 11th floor of the North Tower. Fire spread through the core to the 9th and 14th floors by igniting the insulation of telephone cables in a utility shaft that ran vertically between floors. Areas at the furthest extent of the fire were extinguished almost immediately and the original fire was put out in a few hours. Most of the damage was concentrated on the 11th floor, fueled by cabinets filled with paper, alcohol-based fluid for office machines, and other office equipment. Fireproofing protected the steel and there was no structural damage to the tower. Other than the damage caused by the fire, a few floors below suffered water damage from the extinguishing of the fires above. At that time, the World Trade Center had no fire sprinkler systems.
February 26, 1993 bombing
On February 26, 1993, at 12:17 p.m., a Ryder truck filled with 1,500 pounds (680 kg) of explosives, planted by Ramzi Yousef, detonated in the underground garage of the North Tower. The blast opened a 100 foot (30 m) hole through five sublevels with the greatest damage occurring on levels B1 and B2 and significant structural damage on level B3. Six people were killed and 50,000 other workers and visitors were left gasping for air within the 110 story towers. Many people inside the North Tower were forced to walk down darkened stairwells that contained no emergency lighting, some taking two hours or more to reach safety.
Yousef fled to Pakistan after the bombing but was arrested in Islamabad in February 1995, and was extradited back to the United States to face trial. Sheikh Omar Abdel Rahman was convicted in 1996 for involvement in the bombing and other plots. Yousef and Eyad Ismoil were convicted in November 1997 for their carrying out the bombing. Four others had been convicted in May 1994 for their involvement in the 1993 bombing. According to a presiding judge, the conspirators' chief aim at the time of the attack was to destabilize the north tower and send it crashing into the south tower, toppling both landmarks.
Following the bombing, floors that were blown out needed to be repaired to restore the structural support they provided to columns. The slurry wall was in peril following the bombing and loss of the floor slabs that provided lateral support against pressure from Hudson River water on the other side. The refrigeration plant on sublevel B5, which provided air conditioning to the entire World Trade Center complex, was heavily damaged. Subsequent to the bombing, the Port Authority installed photoluminescent markings in the stairwells. The fire alarm system for the entire complex needed to be replaced because critical wiring and signaling in the original system was destroyed. As a memorial to the victims of the bombing of the tower, a reflecting pool was installed with the names of those who had been killed in the blast. However, the memorial was destroyed following the September 11 attacks. Names of the victims of the 1993 bombing are included in the National September 11 Memorial & Museum.
January 14, 1998 robbery
In January 1998, Mafia member Ralph Guarino, who had gained maintenance access to the World Trade Center, arranged a three-man crew for a heist that netted over $2 million from a Brinks delivery to the eleventh floor of the World Trade Center.
In 1998, the Port Authority approved plans to privatize the World Trade Center. In 2001, the Port Authority sought to lease the World Trade Center to a private entity. Bids for the lease came from Vornado Realty Trust, a joint bid between Brookfield Properties Corporation and Boston Properties, and a joint bid by Silverstein Properties and The Westfield Group. By privatizing the World Trade Center, it would be added to the city's tax rolls and provide funds for other Port Authority projects. On February 15, 2001, the Port Authority announced that Vornado Realty Trust had won the lease for the World Trade Center, paying $3.25 billion for the 99-year lease. Vornado outbid Silverstein by $600 million though Silverstein upped his offer to $3.22 billion. However, Vornado insisted on last minute changes to the deal, including a shorter 39-year lease, which the Port Authority considered nonnegotiable. Vornado later withdrew and Silverstein's bid for the lease to the World Trade Center was accepted on April 26, 2001, and closed on July 24, 2001.
On September 11, 2001, Islamist terrorists hijacked American Airlines Flight 11 and crashed it into the northern façade of the North Tower at 8:46:40 a.m., the aircraft striking between the 93rd and 99th floors. Seventeen minutes later, at 9:03:11 a.m., a second team of terrorists crashed the similarly hijacked United Airlines Flight 175 into the southern facade of the South Tower, striking it between the 77th and 85th floors. The damage caused to the North Tower by Flight 11 destroyed any means of escape from above the impact zone, trapping 1,344 people. Flight 175 had a much more off-centered impact compared to Flight 11, and a single stairwell was left intact; however, only a few people managed to pass through it successfully before the tower collapsed. Although the South Tower was struck lower than the North Tower, thus affecting more floors, a smaller number, fewer than 700, were killed instantly or trapped.
At 9:59 a.m., the South Tower collapsed after burning for approximately 56 minutes. The fire caused steel structural elements, already weakened from the plane impact, to fail. The North Tower collapsed at 10:28 a.m., after burning for approximately 102 minutes. At 5:20 p.m. on September 11, 2001, 7 World Trade Center started to collapse with the crumble of the east penthouse, and it collapsed completely at 5:21 p.m. owing to uncontrolled fires causing structural failure.
The 3 World Trade Center, a Marriott hotel, was destroyed during the collapse of the two towers. The three remaining buildings in the WTC plaza were extensively damaged by debris and later were demolished. The Deutsche Bank Building across Liberty Street from the World Trade Center complex was later condemned owing to the uninhabitable toxic conditions inside; it was deconstructed, with work completed in early 2011. The Borough of Manhattan Community College's Fiterman Hall at 30 West Broadway was also condemned owing to extensive damage in the attacks and is slated for deconstruction.
In the immediate aftermath of the attacks, media reports suggested that tens of thousands might have been killed in the attacks, as over 50,000 people could be inside the towers. Ultimately, 2,753 death certificates (excluding those for hijackers) were filed relating to the 9/11 attacks in New York, including one filed for Felicia Dunn-Jones, who was added to the official death toll in May 2007; Dunn-Jones died five months later from a lung condition linked to exposure to dust during the collapse of the World Trade Center. Three other victims were then added to the official death toll by the city medical examiner's office: Dr. Sneha Anne Philip, who was last seen the day before the attacks; Leon Heyward, a man who developed lymphoma and subsequently died in 2008 as a result of dust ingestion during the events following the attacks to the Twin Towers; and Jerry Borg, who died in December 2010 of pulmonary sarcoidosis determined in June 2011 to be the result of dust from the attacks. Cantor Fitzgerald L.P., an investment bank on the 101st–105th floors of One World Trade Center, lost 658 employees, considerably more than any other employer, while Marsh & McLennan Companies, located immediately below Cantor Fitzgerald on floors 93–101 (the location of Flight 11's impact), lost 295 employees, and 175 employees of Aon Corporation were killed. In addition, 343 of the dead were New York City firefighters, 84 were Port Authority employees, of whom 37 were members of the Port Authority Police Department, and another 23 were New York City Police Department officers. Ten years after the attacks, only 1,629 victims have been identified. Of all the people who were still in the towers when they collapsed, only 20 were pulled out alive.
After years of delay and controversy, reconstruction at the World Trade Center site is now well underway. The new complex will include One World Trade Center (formerly known as the Freedom Tower), 7 World Trade Center, three other high-rise office buildings, a museum and memorial, and a transportation hub similar in size to Grand Central Terminal. Both One and Four World Trade Center are on track for completion and occupancy by 2013. The 9/11 memorial is complete, with the museum set to open in 2013. Two and Three World Trade Center, as well as the Transportation Hub, are also making progress, set to be finished by around 2015.
|Planned rebuilding of the
World Trade Center
|One World Trade Center (Tower 1)|
|Two World Trade Center (Tower 2)|
|Three World Trade Center (Tower 3)|
|Four World Trade Center (Tower 4)|
|Five World Trade Center (Tower 5)|
|Seven World Trade Center (Tower 7)|
|Memorial and museum|
|National September 11 Memorial & Museum|
The process of cleanup and recovery continued 24 hours a day over a period of eight months. Debris was transported from the World Trade Center site to Fresh Kills on Staten Island, where it was further sifted. On May 30, 2002, a ceremony was held to officially mark the end of the cleanup efforts. In 2002, ground was broken on construction of a new 7WTC building located just to the north of the main World Trade Center site. Since it was not part of the site master plan, Larry Silverstein was able to proceed without delay on the rebuilding of 7 World Trade Center, which was completed and officially opened in May 2006; this had been considered a priority since restoring the Consolidated Edison Cos. electrical substation in the building's lower floors was necessary to meet power demands of Lower Manhattan. While 7 World Trade Center was not part of the master plan for the Twin Towers site, Silverstein and Con Edison recognized that the rebuilding of 7 World Trade Center would have to be consistent with the master plan which was expected to re-open the street grid which had been blocked by the original World Trade Center super-block. As a result, the design for the new 7 World Trade Center allowed for the re-opening of Greenwich Street, which had been blocked by the original 7 World Trade Center. A temporary PATH station at the World Trade Center opened in November 2003; it will be replaced by a permanent station designed by Santiago Calatrava.
With the main World Trade Center site, numerous stakeholders were involved including Silverstein and the Port Authority, which in turn meant the Governor of New York State, George Pataki, had some authority. In addition, the victims' families, people in the surrounding neighborhoods, Mayor Michael Bloomberg, and others wanted input. Governor Pataki established the Lower Manhattan Development Corporation (LMDC) in November 2001 as an official commission to oversee the rebuilding process. The LMDC held a competition to solicit possible designs for the site. The Memory Foundations design by Daniel Libeskind was chosen as the master plan for the World Trade Center site. The plan included the 1,776 feet (541 m) Freedom Tower (now known as One World Trade Center) as well as a memorial and a number of other office towers. Out of the World Trade Center Site Memorial Competition, a design by Michael Arad and Peter Walker titled Reflecting Absence was selected in January 2004.
On March 13, 2006, workers arrived at the World Trade Center site to remove remaining debris and start surveying work. This marked the official start of construction of the National September 11 Memorial & Museum, though not without controversy and concerns from some family members. In April 2006, the Port Authority and Larry Silverstein reached an agreement in which Silverstein ceded rights to develop the Freedom Tower and Tower Five in exchange for financing with Liberty Bonds for Towers Two, Three, and Four. On April 27, 2006, a ground-breaking ceremony was held for the Freedom Tower.
In May 2006, architects Richard Rogers and Fumihiko Maki were announced as the architects for Towers Three and Four, respectively. The final designs for Towers Two, Three and Four were unveiled on September 7, 2006. Tower Two, or 200 Greenwich Street, will have a roof height of 1,254 feet (382 m) and a 96 feet (29 m) tripod spire for a total of 1,350 feet (410 m). Tower Three, or 175 Greenwich Street will have a roof height of 1,155 feet (352 m) and an antenna height reaching 1,255 feet (383 m). Tower Four, or 150 Greenwich Street, will have an overall height of 946 feet (288 m). On June 22, 2007, the Port Authority of New York and New Jersey announced that JP Morgan Chase will build Tower 5, a 42-story building on Site 5 occupied by the Deutsche Bank Building, and Kohn Pedersen Fox was selected as the architect for the building. Four renowned architects, including Spanish architect Santiago Calatrava, who designed the transit hub, One WTC designer David Childs of Skidmore, Owings and Merrill, and the famed British architect Norman Foster of Foster and Partners designed Tower Two and masterminded the iconic diamond design, will greatly enhance the street-level atmosphere of the rebuilt site. The projects will be complete between early 2013 to mid-2014.
As of August 2011, One World Trade Center is at 80 stories with glass up to the 54th floor, Tower Four is up around 38 stories with glass up to the 15th floor, and the former Deutsche Bank Building has been completely dismantled and the Port Authority is working on their Vehicle Security Center. The World Trade Center Transportation Hub's PATH hall is nearly complete. The memorial officially opened to relatives of the deceased on September 11, 2011, and to the general public on September 12. World Trade Center Tower Three's foundations are becoming visible, and will be completed in mid-2014 if Silverstein Properties can meet requirements set by the Port Authority, as they very likely will. Tower Two will also be completed on schedule according to the construction company. In the December of 2011, Tower Two's foundations are finished and is starting to assemble the frame.  Because numerous American and Chinese companies are "very interested" in leasing space at the WTC, Two World Trade Center is likely to be finished earlier than expected. Publishing Giant Conde Nast has agreed to move its headquarters to One World Trade Center, and with this shift, many more are expected to follow.
Controversy and criticism
There was much debate regarding the future of Ground Zero following the destruction of the World Trade Center. Disagreement and controversy regarding who owned the property and what would be built there hindered construction at the site for several years. Many wanted the Twin Towers to be rebuilt, but stronger and taller. This movement was led by an informal organization called the Twin Towers Alliance. Others, considering the area sacred, did not want anything built there at all or wanted the entire site to become a memorial. Finally, a master plan was agreed upon, which would feature a memorial and museum where the original twin towers stood and six new skyscrapers surrounding it.
One World Trade Center itself has been met with criticism. The original design, which was asymmetrical, significantly shorter, and called for an off-center spire, was met with much disapproval, causing a new one to be devised. A key feature of the final design, the fortified, windowless base, was also denounced as looking dreary and unwelcoming. To alleviate this problem, the designers decided to clad it with prismatic glass panels. Since the failure of that plan, it is now unclear what the base will be covered with. The name change from Freedom Tower to One World Trade Center was met with some criticism. Governor of New York George Pataki stated in 2003 that, "The Freedom Tower isn't going to be One World Trade Center, it's going to be the Freedom Tower."
- World Trade Center in popular culture
- Construction of One World Trade Center
- Project Rebirth
- The Philippe Petit High Wire Walk Between the Towers
- The Sphere
- World Trade Center at Emporis
- "New World Trade Center climbs to 100 stories". Associated Press. April 2, 2012.
- Staff. Consumer Price Index (estimate) 1800–2012. Federal Reserve Bank of Minneapolis. Retrieved March 31, 2013.
- Holusha, John (January 6, 2002). "Commercial Property; In Office Market, a Time of Uncertainty". The New York Times. Retrieved November 21, 2008.
- "Ford recounts details of Sept. 11". Real Estate Weekly (BNET). February 27, 2002. Retrieved January 3, 2009.
- "Man's death from World Trade Center dust brings Ground Zero toll to 2,753". NY Daily News. Associated Press. June 18, 2011. Retrieved September 1, 2011.
- "Dewey Picks Board for Trade Center". The New York Times. July 6, 1946.
- "Lets Port Group Disband, State Senate for Dissolution of World Trade Corporation". The New York Times. March 11, 1949.
- Gillespie (1999), pp. 32–33
- Gillespie (1999), pp. 34–35
- Gillespie (1999), p. 38
- Grutzner, Charles (December 29, 1961). "Port Unit Backs Linking of H&M and Other Lines". The New York Times.
- Cudahy (2002), p. 56
- Wright, George Cable (January 23, 1962). "2 States Agree on Hudson Tubes and Trade Center". The New York Times.
- Smith, Terence (August 4, 1966). "City Ends Fight with Port Body on Trade Center". The New York Times.
- Smith, Terence (January 26, 1967). "Mayor Signs Pact on Trade Center". The New York Times.
- Esterow, Milton (September 21, 1962). "Architect Named for Trade Center". The New York Times.
- Huxtable, Ada Louise (January 19, 1964). "A New Era Heralded". The New York Times.
- Huxtable, Ada Louise (January 26, 1964). "Biggest Buildings Herald New Era". The New York Times.
- Gillespie (1999), p. 76
- Lew, H.S., Richard W. Bukowski, Nicholas J. Carino (September 2005). "Design, Construction, and Maintenance of Structural and Life Safety Systems (NCSTAR 1-1)". National Institute of Standards and Technology. p. 9.
- Gillespie (1999), pp. 75–78
- Ruchelman (1977), p. 11
- NIST NCSTAR 1-1 (2005), p. 7
- Pekala, Nancy (November 1, 2001). "Profile of a lost landmark; World Trade Center". Journal of Property Management.
- Huxtable, Ada Louise (May 29, 1966). "Who's Afraid of the Big Bad Buildings". The New York Times.
- Darton (1999), pp. 32–34
- Nobel, Philip (2005). Sixteen Acres: Architecture and the Outrageous Struggle for the Future of Ground Zero. Macmillan. p. 54. ISBN 0-8050-8002-3.
- NIST NCSTAR 1 (2005), p. 1
- NIST NCSTAR 1-1 (2005), pp. 40–42
- NIST NCSTAR 1 (2005), p. 8
- NIST NCSTAR 1 (2005), pp. 8–9
- NIST NCSTAR 1 (2005), p. 10
- "New York: A Documentary Film – The Center of the World (Construction Footage)". Port Authority / PBS. Retrieved May 16, 2007.
- Glanz and Lipton (2003), p. 138
- NIST NCSTAR 1-1A (2005), p. 65
- Glanz and Lipton (2004), pp. 139–144
- Glanz and Lipton (2004), pp. 160–167
- Ingraham, Joseph C. (March 29, 1965). "Port Agency Buys Downtown Tract". The New York Times.
- Gillespie (1999), p. 61
- Federal Emergency Management Agency (May 2002). "Chapter 1". World Trade Center Building Performance Study. ISBN 0-16-067389-5. Retrieved June 9, 2011.
- Iglauer, Edith (November 4, 1972). "The Biggest Foundation". The New Yorker. Archived from the original on December 18, 2001.
- Kapp, Martin S (July 9, 1964). "Tall Towers will Sit on Deep Foundations". Engineering News Record.
- Gillespie (1999), p. 68
- Gillespie (1999), p. 71
- "New York Gets $90 Million Worth of Land for Nothing". Engineering News Record. April 18, 1968.
- "Contracts Totaling $74,079,000 Awarded for the Trade Center". The New York Times. January 24, 1967.
- Kihss, Peter (February 27, 1967). "Trade Center Job To Go To Tishman". The New York Times.
- "Timeline: World Trade Center chronology". PBS – American Experience. Retrieved May 15, 2007.
- Carroll, Maurice (December 30, 1968). "A Section of the Hudson Tubes is Turned into Elevated Tunnel". The New York Times.
- NIST NCSTAR 1-1, p. xxxvi
- Cudahy (2002), p. 58
- Gillespie (1999), p. 134
- Gillespie (1999), pp. 42–44
- Clark, Alfred E. (June 27, 1962). "Injunction Asked on Trade Center". The New York Times.
- Arnold, Martin (November 13, 1963). "High Court Plea is Lost by Foes of Trade Center". The New York Times.
- Gillespie (1999), pp. 49–50
- Knowles, Clayton (February 14, 1964). "New Fight Begun on Trade Center". The New York Times.
- Eric Jaffe (September 12, 2012). "The World Trade Center's Rocky Real Estate History". The Atlantic Cities. Atlantic Media Company. Retrieved September 11, 2012.
- "Kheel Urges Port Authority to Sell Trade Center". The New York Times. November 12, 1969.
- Steese, Edward (March 10, 1964). "Marring City's Skyline". The New York Times.
- Whitman, Alden (March 22, 1967). "Mumford Finds City Strangled By Excess of Cars and People". The New York Times.
- Alex Sparburg Alexiou (2006), Jane Jacobs: Urban Visionary, New Brunswick: Rutgers; ISBN 978-0-8135-3792-4; p. 78.
- Mumford, Lewis (1970). The Pentagon of Power. Harcourt Brace Jovanovich. p. 342. ISBN 0-15-163974-4.
- Dunlap, David W (December 7, 2006). "At New Trade Center, Seeking Lively (but Secure) Streets". The New York Times.
- Dunlap, David W (March 25, 2004). "Girding Against Return of the Windy City in Manhattan". The New York Times.
- "World Trade Center Plaza Reopens with Summer-long Performing Arts Festival". Port Authority of New York and New Jersey. June 9, 1999.
- "1973: World Trade Center Is Dynamic Duo of Height". Engineering News-Record. August 16, 1999. Archived from the original on June 11, 2002.
- Mcdowell, Edwin (April 11, 1997). "At Trade Center Deck, Views Are Lofty, as Are the Prices". The New York Times. Retrieved September 12, 2009.
- "Willis Tower Building Information". Retrieved December 1, 2008.
- Deutsch, Claudia H (February 26, 1995). "Commercial Property/World Trade Center; Attuning a Huge Concourse to an Upscale Trade". The New York Times. Retrieved April 11, 2013.
- "Air-Cooled PATH Terminal in World Trade Center Opens Tuesday". The New York Times. July 1, 1971. p. 94. Retrieved May 30, 2010.
- "Office locations". Cantor Fitzgerald. March 4, 2000. Retrieved on October 4, 2009.
- "About the Port Authority." Port Authority of New York and New Jersey. June 22, 2000. Retrieved on January 22, 2010.
- "World Trade Center Building Performance Study" (PDF). Federal Emergency Management Agency. Retrieved March 8, 2007. "Six 1,200-kilowatt (kW) emergency power generators located in the sixth basement (B-6) level provided a secondary power supply."
- Fischbach, Amy Florence (January 1, 2001). "Towering security". CEE News. Archived from the original on October 21, 2006. Retrieved March 8, 2007. "E-J Electric set four generators on the roof of Tower 5, which was nine stories, as opposed to the 110-story Towers 1 and 2. E-J then ran high-voltage feeder cable to Towers 1, 2, 4 and 5, installed three substations and distributed power to the tenants."
- Onishi, Norimitsu (February 24, 1997). "Metal Detectors, Common at Other City Landmarks, Are Not Used". The New York Times. Retrieved November 21, 2008.
- McDowell, Edwin (April 11, 1997). "At Trade Center Deck, Views Are Lofty, as Are the Prices". The New York Times. Retrieved November 21, 2008.
- Darton (1999), p. 152
- Adams, Arthur G. (1996). The Hudson River Guidebook. Fordham University Press. p. 87. ISBN 0-8232-1679-9.
- Zraly, Kevin (2006). Windows on the World Complete Wine Course. Sterling Publishing Company. p. 260. ISBN 1-4027-2639-2.
- Grimes, William (September 19, 2001). "Windows That Rose So Close To the Sun". The New York Times.
- Greenhouse, Steven (June 4, 2002). "Windows on the World Workers Say Their Boss Didn't Do Enough". The New York Times.
- Rediff.com. Reuters, November 17, 2001: Buried WTC gold returns to futures trade. Retrieved December 1, 2008.
- Darton (1999), p. 204
- Darton (1999), p. 8
- Olshan, Jeremy (February 4, 2003). "'Not Deliverable';Mail still says 'One World Trade Center'". Newsday (New York).
- Gillespie (1999), p. 5
- Glanz and Lipton (2003), p. 219
- Gillespie (1999), p. 149
- "Skyscrapers. – Goodwin, Dan "Spider Dan" World Trade Center climb (1983), p 169". National Geographic magazine. February 1989. Retrieved January 30, 2011.
- "Skyscraper Defense". Retrieved July 4, 2011.
- Byrne, Robert (September 19, 1995). "Kasparov Gets Pressure, but No Victory". The New York Times. Retrieved November 21, 2008.
- "Trade Center Hit by 6-Floor Fire". The New York Times. February 14, 1975. Retrieved September 11, 2008.
- "The Emergency Response Operations" (PDF). Federal Building and Fire Safety Investigation of the World Trade Center Disaster. NIST. October 2005. Retrieved September 11, 2008.
- Reeve (1999), p. 10
- Lew, H.S., Richard W. Bukowski, Nicholas J. Carino (September 2005). Design, Construction, and Maintenance of Structural and Life Safety Systems (NCSTAR 1-1). National Institute of Standards and Technology. pp. xlv.
- Mathews, Tom (March 8, 1993). "A Shaken City's Towering Inferno". Newsweek. Retrieved October 26, 2008.
- Barbanel, Josh (February 27, 1993). "Tougher Code May Not Have Helped". The New York Times. Retrieved November 20, 2008.
- Johnston, David (February 9, 1995). "Fugitive in Trade Center Blast Is Caught and Returned to U.S.". The New York Times. Retrieved November 20, 2008.
- Fried, Joseph P. (January 18, 1996). "Sheik Sentenced to Life in Prison in Bombing Plot". The New York Times. Retrieved November 20, 2008.
- "Jury convicts 2 in Trade Center blast". CNN. November 12, 1997. Retrieved November 20, 2008.
- Hays, Tom and Larry Neumeister (May 25, 1994). "In Sentencing Bombers, Judge Takes Hard Line". Seattle Times / AP. Retrieved November 20, 2008.
- "Prosecutor: Yousef aimed to topple Trade Center towers". CnN. August 5, 1997. Retrieved November 20, 2008.
- Port Authority Risk Management Staff. "The World Trade Center Complex" (PDF). United States Fire Administration. Retrieved May 15, 2007.
- Ramabhushanam, Ennala and Marjorie Lynch (1994). "Structural Assessment of Bomb Damage for World Trade Center". Journal of Performance of Constructed Facilities 8 (4): 229–242. doi:10.1061/(ASCE)0887-3828(1994)8:4(229).
- Amy, Jr., James D. (December 2006). "Escape from New York – The Use of Photoluminescent Pathway-marking Systems in High-Rise". Emerging trends (Society of Fire Protection Engineer). Issue 8. Retrieved November 20, 2008.
- Evans, David D., Richard D. Peacock, Erica D. Kuligowski, W. Stuart Dols, William L. Grosshandler (September 2005). Active Fire Protection Systems (NCSTAR 1–4) (PDF). National Institute of Standards and Technology. p. 44.
- Dwyer, Jim (February 26, 2002). "Their Monument Now Destroyed, 1993 Victims Are Remembered". The New York Times. Retrieved November 20, 2008.
- Reppetto, Thomas (2007). Bringing Down the Mob: The War Against the American Mafia. Macmillan. p. 279. ISBN 0-8050-8659-5.
- Herman, Eric (February 6, 2001). "PA to ease WTC tax load, rent would be cut to offset hike by city". New York Daily News.
- Bagli, Charles V. (January 31, 2001). "Bidding for Twin Towers". The New York Times. Retrieved November 20, 2008.
- Cuozzo, Steve (January 30, 2001). "Larry Lusts for Twin Towers; Silverstein has an Eye on WTC's; Untapped Retail Potential". New York Post.
- Herman, Eric (January 31, 2001). "Port Authority Gets Final Bids on WTC". New York Daily News.
- "Brookfield Loses Lease Bid". Toronto Star. February 23, 2001.
- Bagli, Charles V. (March 20, 2001). "As Trade Center Talks Stumble, No. 2 Bidder Gets Another Chance". The New York Times. Retrieved November 20, 2008.
- Bagli, Charles V. (April 27, 2001). "Deal Is Signed To Take Over Trade Center". The New York Times. Retrieved November 20, 2008.
- Smothers, Ronald (July 25, 2001). "Leasing of Trade Center May Help Transit Projects, Pataki Says". The New York Times. Retrieved November 20, 2008.
- "9/11 Commission Report". The National Commission on Terrorist Attacks Upon the United States.
- Dwyer, Jim; Lipton, Eric et al. (May 26, 2002). "102 Minutes: Last Words at the Trade Center; Fighting to Live as the Towers Die". The New York Times. Archived from the original on October 10, 2008. Retrieved May 23, 2008.
- Lipton, Eric (July 22, 2004). "Study Maps the Location of Deaths in the Twin Towers". The New York Times. Retrieved April 22, 2008.[dead link]
- NIST NCSTAR 1-1 (2005), p. 34; pp. 45–46
- "FEMA 403 -World Trade Center Building Performance Study, Chapter. 5, section 5.5.4" (PDF). Retrieved January 30, 2011.
- "Final Report on the Collapse of World Trade Center Building 7 – Draft for Public Comment". NIST. August 2008. pp. xxxii.
- "World Trade Center Building Performance Study". FEMA. May 2002. Retrieved June 9, 2011.
- "World Trade Center Building Performance Study – Bankers Trust Building". FEMA. May 2002. Retrieved July 12, 2007.
- "The Deutsche Bank Building at 130 Liberty Street". Lower Manhattan Construction Command Center. Retrieved July 12, 2007.
- "Fiterman Hall – Project Updates". Lower Manhattan Construction Command Center. Retrieved November 19, 2008.
- DePalma, Anthony (May 24, 2007). "For the First Time, New York Links a Death to 9/11 Dust". The New York Times.
- "Official 9/11 Death Toll Climbs By One". CBS News. Associated Press. July 10, 2008. Retrieved August 29, 2010.
- Foderaro, Lisa W. (September 11, 2009). "9/11's Litany of Loss, Joined by Another Name". The New York Times. Retrieved August 29, 2010.
- "Cantor rebuilds after 9/11 losses". BBC News (London). September 4, 2006. Retrieved May 20, 2008.
- Siegel, Aaron (September 11, 2007). "Industry honors fallen on 9/11 anniversary". InvestmentNews. Retrieved May 20, 2008.
- Grady, Denise; Revkin, Andrew C. (September 10, 2002). "Lung Ailments May Force 500 Firefighters Off Job". The New York Times. Retrieved May 23, 2008.
- "Post-9/11 report recommends police, fire response changes". USA Today (Washington DC). Associated Press. August 19, 2002. Retrieved May 23, 2008.
- "Police back on day-to-day beat after 9/11 nightmare". CNN. July 21, 2002. Retrieved May 23, 2008.
- Lemre, Jonathan (August 24, 2011). "Remains of WTC worker Ernest James, 40, ID'd ten years after 9/11". New York Daily News. Retrieved August 25, 2011.
- Denerstein, Robert (August 4, 2006). "Terror in close-up". Rocky Mountain News (Denver, CO). Retrieved November 19, 2008.
- "Lower Manhattan : 1 World Trade Center". Lowermanhattan.info. Retrieved 2011-12-11.
- "Lower Manhattan : 4 World Trade Center (150 Greenwich Street)". Lowermanhattan.info. 2006-09-08. Retrieved 2011-12-11.
- "National September 11 Memorial & Museum | World Trade Center Memorial". 911memorial.org. 2011-12-07. Retrieved 2011-12-11.
- "Ceremony closes 'Ground Zero' cleanup". CNN. May 30, 2002. Retrieved September 11, 2008.
- Bagli, Charles V. (January 31, 2002). "Developer's Pace at 7 World Trade Center Upsets Some". The New York Times. Retrieved February 17, 2008.
- "7 World Trade Center Opens with Musical Fanfare". Lower Manhattan Development Corporation (LMDC). May 22, 2006. Retrieved July 27, 2007.
- "Major Step at Ground Zero: 7 World Trade Center Opening". Architectural Record. May 17, 2006. Retrieved February 17, 2008.
- "Experts Discuss Planning, Designing and Rebuilding World Trade Center". Cornell Chronicle. July 27, 2011.
- "Urban Design and Visual Resources (Chapter 7)" (PDF). Permanent WTC Path Terminal Final Environmental Impact Statement and Section 4(f) Evaluation. Port Authority of New York and New Jersey. May 2005. Archived from the original on March 6, 2008. Retrieved November 19, 2008.
- Pérez-Peña, Richard (November 3, 2001). "State Plans Rebuilding Agency, Perhaps Led by Giuliani". The New York Times. Retrieved November 19, 2008.
- Lower Manhattan Development Corporation. "Selected Design for the WTC Site as of February 2003". Retrieved November 19, 2008.
- Collins, Glenn and David W. Dunlap (January 15, 2004). "Unveiling of Memorial Reveals a Wealth of New Details". The New York Times. Retrieved November 19, 2008.[dead link]
- Katersky, Aaron (March 13, 2006). "Construction on Ground Zero Memorial Ignites Protests". ABC News. Retrieved November 19, 2008.
- Dunlap, David W. (April 28, 2006). "Freedom Tower Construction Starts After the Beginning". The New York Times. Retrieved November 19, 2008.
- Todorovich, Petra (March 24, 2006). "At the Heart of Ground Zero Renegotiations, a 1,776-Foot Stumbling Block". Spotlight on the Region (Regional Plan Association) 5 (6). Archived from the original on June 5, 2008. Retrieved November 19, 2008.
- Westfeldt, Amy (April 28, 2006). "Construction Begins at Ground Zero". Washington Post / AP. Retrieved November 19, 2008.
- Pogrebin, Robin (May 3, 2006). "Richard Rogers to Design Tower at Ground Zero". The New York Times. Retrieved November 19, 2008.
- Dunlap, David W. (September 7, 2006). "Designs Unveiled for Freedom Tower’s Neighbors". The New York Times. Retrieved November 19, 2008.
- Bagli, Charles V. (June 14, 2007). "Chase Bank Set to Build Tower by Ground Zero". The New York Times. Retrieved November 19, 2008.
- Appelbaum, Alec (July 30, 2007). "Kohn Responds to WTC5 Criticisms". Architectural Record. Retrieved November 19, 2008.
- Goldman, Henry (September 7, 2010). "World Trade Center Rebuilding May Finish by 2014, Officials Say || News || World Trade Center". WTC.com. Retrieved September 12, 2011.
- Shapiro, Julie (February 8, 2011). "Deutsche Bank Demolition Finally Reaches Street Level || News || World Trade Center". WTC.com. Retrieved September 12, 2011.
- "World Trade Center deal may hasten rebuilding". Reuters. August 26, 2010.
- "3 World Trade Center || About the WTC || World Trade Center". WTC.com. Retrieved September 12, 2011.
- "Two World Trade Center on Emporis". Retrieved 30 December 2011.
- Rubinstein, Dana (October 20, 2010). "Everybody Go Downtown! || News || World Trade Center". WTC.com. Retrieved September 12, 2011.
- Bagli, Charles V. (August 3, 2010). "Condé Nast Signs Deal to Move to Ground Zero Tower". The New York Times.
- "Trump pushes own Ground Zero plan". CNN. May 19, 2005.
- "Freedom Tower Name Change Slammed as Unpatriotic". Fox News.com. Associated Press. March 28, 2009.
- Cuthbertson, Charlotte (last updated April 2, 2009). "Freedom Tower Renaming Draws Criticism". The Epoch Times. Retrieved October 31, 2010.
- Cudahy, Brian J. (2002). Rails Under the Mighty Hudson. Fordham University Press. ISBN 0-8232-2190-3.
- Darton, Eric (1999). Divided We Stand: A Biography of New York's World Trade Center. Basic Books. ISBN 0-465-01727-4.
- Fanella, David A., Arnaldo T. Derecho, S.K. Ghosh (September 2005). Design and Construction of Structural Systems (NCSTAR 1-1A) (PDF). Final Report on the Collapse of the World Trade Center Towers. National Institute of Standards and Technology (NIST).
- Gillespie, Angus K. (1999). Twin Towers: The Life of New York City's World Trade Center. Rutgers University Press. ISBN 0-8135-2742-2.
- Glanz, James and Eric Lipton (2003). City in the Sky. Times Books. ISBN 0-8050-7428-7.
- Lew, H.S., Richard W. Bukowski, Nicholas J. Carino (September 2005). Design, Construction, and Maintenance of Structural and Life Safety Systems (NCSTAR 1-1) (PDF). Final Reports of the Federal Building and Fire Investigation of the World Trade Center Disaster. National Institute of Standards and Technology (NIST).
- Reeve, Simon (1999). The New Jackals: Ramzi Yousef, Osama bin Laden and the Future of Terrorism. Northeastern University Press. ISBN 1-55553-509-7.
- Ruchelman, Leonard I. (1977). The World Trade Center: Politics and Policies of Skyscraper Development. Syracuse University Press. ISBN 0-8156-2180-9.
- National Construction Safety Team (September 2005). Federal Building and Fire Safety Investigation of the World Trade Center Disaster (NCSTAR 1–6) (PDF). Structural Fire Response and Probable Collapse Sequence of the World Trade Center Towers. National Institute of Standards and Technology (NIST).
- "World Trade Center Building Performance Study". Federal Emergency Management Agency. May 2002. Retrieved June 9, 2011.
|Wikimedia Commons has media related to: World Trade Center (New York)|
- World Trade Center – Silverstein Properties
- World Trade Center – Port Authority of New York & New Jersey
- World Trade Center Progress – Port Authority of New York & New Jersey
- National September 11 Memorial & Museum at the World Trade Center
- World Trade Center at the Open Directory Project
- Building the Twin Towers: A Tribute – slideshow by Life magazine
- New York: A Documentary film features the construction and destruction of the World Trade Center in the seventh and final episode of the series directed by Ric Burns.
- Historic video with scenes of World Trade Center under construction in 1970
Empire State Building
|Tallest building in the world
|Tallest building in the United States
|Building with the most floors
City National Plaza
|Tallest twin towers in the world