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There are several definitions for the term "lockdown"; the most common definitions pertain to a state of containment or a restriction of progression. A lockdown is an emergency protocol to prevent people or information from escaping, which usually can only be ordered by someone in command. Lockdowns are also used to protect people inside a facility or, for example, a computing system, from a dangerous external event.

Of buildings, a partial lockdown means that the doors leading outside the building are locked and people may not exit or enter the building. A full lockdown means that people must stay where they are and may not exit or enter a classroom, apartment unit, store unit, an office space, condo unit or the building. If people are in a hallway they must go into the nearest classroom, apartment unit, condo unit, office space or store unit.



Lockdown procedures vary by school district. Generally, a lockdown means that interior and exterior doors are locked, and all students and staff must remain in their location from the time the lockdown is announced. Windows are covered, and students are to stay away from windows.[1]

Since the early 2000s, lockdown procedures in schools have been constantly changing. Some schools direct teachers to continue with standard procedures while remaining quiet, while some recommend an active approach against threats.[2]


In its most common usage in corrections units, the term lockdown can be defined as a course of action to control the movement of inmates. Confining all prisoners, except workers, to their cells until the end of the day is an example of a "lockdown period" in a corrections schedule. However a "full lockdown" is used when all prisoners are locked in their cells to prevent a riot or unrest from spreading or during an emergency.


In US guidelines, occasions for preventing entry into a hospital may include: power failure, earthquake, flooding, fire, bomb threat, hostage crisis and active shooter.[3][4] Occasions for preventing both entry and exit from a hospital may include: external contamination, civil disturbance and abduction of an infant or child.[3][4]

Lean manufacturing process[edit]

In manufacturing, the term lockdown event refers to a continuous improvement initiative in which manufacturing in a specific area (typically a cell or specific piece of machinery) is halted in order to contain, and determine, what are the issues that are preventing the manufacture of goods from meeting the quality specifications. During the lockdown event a multi disciplinary team reviews the specific area manufacturing processes, tooling and machine condition, to find the root cause(s) of the problem(s). Once changes to the process, or machine repairs that may include adjustments and/or replacement are effected, a sample run is initiated and evaluated. If the results of the validation are within the required specifications, the area lockdown is lifted and production is resumed. Follow up sampling is conducted subsequently to ensure continuity of the lockdown results.

Historical events[edit]

In the wake of the September 11 attacks (2001), a three-day lockdown of American civilian airspace was initiated.

In December 2005, the New South Wales Police Force (NSW Police Force) initiated a lockdown of the Sutherland Shire and other beach areas of New South Wales to contain race rioting (and retaliative strikes). The New South Wales Labor government, in an emergency sitting of parliament, passed an array of amendments to legislation giving the NWS Police Force additional powers to 'lock down' targeted areas and roads within New South Wales. The legislation introduced to deal with the 2005 Cronulla riots was the Law Enforcement Legislation Amendment (Public Safety) Act 2005 (NSW). The Law Enforcement Legislation Amendment (Public Safety) Act 2005 (NSW) amended four separate pieces of legislation:

Under their new powers, the NSW Police Force locked down targeted areas and roads at Cronulla, Bondi, Coogee, Maroubra and Brighton-le-Sands to prevent persons of Middle Eastern appearance from committing reprisal attacks and prevent white supremacist agitators from further violence.

An example of a campus/school lockdown was demonstrated at the University of British Columbia (UBC) on January 30, 2008, when an unknown threat was made and the Royal Canadian Mounted Police (RCMP) issued a lockdown on one of the buildings on campus for six hours, cordoning off the area, and a campus alert was sent via email to everyone affiliated with UBC while students and faculties were to remain locked in the building.[5][6][7]

On April 10, 2008, two Canadian secondary schools were locked down due to suspected firearm threats. George S. Henry Academy was locked down in Toronto, Ontario at approximately 2:00 p.m.[8] The Emergency Task Force (TPS) were contacted and the lockdown lasted for more than two hours. New Westminster Secondary School was locked down in New Westminster, British Columbia at approximately 1:40 p.m.[9] The Emergency Response Team (ERT) were called and the school was under lockdown until 4:30 p.m. Due to the size of the school some students were not able to leave until 7:00 p.m.

On 19 April 2013, the entire city of Boston was locked down and all public transportation stopped during the manhunt for Islamist terrorist Dzhokhar and Tamerlan Tsarnaev, the suspects of the Boston Marathon bombing, while the town of Watertown was under heavy-armed police and SWAT surveillance, as well as systematic house-to-house searches.[10][11][12]

In the 2015 Brussels lockdown, the city was locked down for days while security services sought suspects involved with the November 2015 Paris attacks. Later in 2015, a terror threat caused the 2015 Los Angeles Unified School District closure.

Additional uses[edit]

  • An air gap is a network security measure that separates a secure network and unsecured networks.
  • Digital lockdown, a block of all outward flows of information on a computer, including Internet access and internal applications, in order to prevent the spread of viral infections and glitches in the computer, or to prevent a computer hijacker from stealing information.
  • A lockdown application is a computer program used during computerized testing that attempts to prevent a user from accessing software other than the test itself.
  • In US protests Lock-ons are often referred to as lockdowns

See also[edit]


  1. ^ "Lockdown Procedures for Schools - GuideOne". GuideOne.
  2. ^ News, A. B. C. (16 December 2012). "School Safety Questioned After Shooting". ABC News.
  3. ^ a b Lockdown Policy from California Hospital Association. Retrieved December 2012
  4. ^ a b Lockdown Policy at Iroquois Healthcare Alliance. Retrieved December 2012
  5. ^ Cause for UBC Lockdown still uncertain but initial posting may reveal some clues
  6. ^ "Police increase presence at UBC following lockdown"
  7. ^ "Threat prompts lockdown at UBC"
  8. ^ "NORTH YORK: Two charged after George S. Henry Academy lockdown"
  9. ^ "Teen arrested in connection with school lockdown" Archived 2009-02-17 at the Wayback Machine.
  10. ^ This Is What It Looks Like When the Police Shut Down a City, The Atlantic Wire, 19 Apr 2013. Retrieved Jun 2013.
  11. ^ A Town Under Siege: Watertown Residents Describe Life Under Lockdown, Time, 19 Apr 2013. Retrieved Jun 2013.
  12. ^ Boston faces lockdown as police hunt for marathon bombing suspect, The Guardian, 19 April 2013. Retrieved 19 April 2013.