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Yuba City bus disaster

Coordinates: 38°01′28″N 122°06′40″W / 38.0244°N 122.1110°W / 38.0244; -122.1110
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Yuba City bus disaster
DateMay 21, 1976
10:55 AM
OperatorStudent Transportation Lines, Inc
CauseBrake failure due to insufficient maintenance, driver training, driver proficiency

The Yuba City bus disaster occurred on May 21, 1976, in Martinez, California. A chartered school bus transporting 52 passengers on an elevated offramp left the roadway, landing on its roof.[1] Of the 52 passengers (not including the driver), 28 students and an adult adviser were killed in the crash.[1]

It remains the deadliest highway disaster ever investigated by the National Transportation Safety Board (NTSB) since its creation.[2]


On May 21, 1976, Yuba City High School chartered a school bus from Student Transportation Lines, Inc. to transport its a cappella choir from Yuba City, California, to Miramonte High School in Orinda for a friendship day involving the choirs of the two schools.[3] The company supplied a Crown bus, dating from 1950.[3][2]

The accident occurred at 10:55 a.m., as the driver, Evan Prothero, 49, of Olivehurst, took the Marina Vista Avenue off-ramp (exit 56) from I-680 southbound from the Benicia–Martinez Bridge. Prothero was unfamiliar with this bus, and mistook the low air pressure warning (for the air brakes) for a warning of low engine oil pressure. Intending to stop for oil,[3] the driver exited the freeway at the aforementioned off ramp; the air brake system failed due to lack of air pressure. With no braking capability, the bus struck the mounted bridge rail and left the elevated roadway. After falling 21.6 feet (6.6 meters), the bus landed on its roof, crushing it to the base of the window line.


Out of 52 passengers on board, twenty-eight students and an adult adviser were killed.[1] All of the surviving passengers were injured, most critically.[3] The driver survived the crash but was seriously hurt.[2]

  1. Larry R. Shearer, 14[4]
  2. Carrie Emmirch, 15
  3. Danielle Cote, 15[5]
  4. Joanne A. Matson, 15[4]
  5. Marla Azim, 15[4]
  6. Bobby R. Ortega, 16[5]
  7. Catherine R. Mudge, 16[4]
  8. Kris Huston, 16 [5]
  9. Larry H. Rooney, 16[5]
  10. Rachel Carlson, 16[5]
  11. Ruth A. Bowen, 16[6]
  12. Carlene Engle 17 [4]
  13. Constance Adkins, 17[7]
  14. Cynthia Graham, 17[8]
  15. Jim Frantz, 17 [5]
  16. Seth Rosebrough, 17[5]
  17. Sharlene Engle, 17[4]
  18. Steven Gust, 17 [4]
  19. Robert Randolph, 17[5]
  20. Robert J. Stafford, 17[4]
  21. Amy Hicks, 18[5]
  22. Bonnie Barfield, 18[5]
  23. Jodie L. McCoy, 18[4]
  24. Lori Killingsworth, 18[5]
  25. Marti A. Melani, 18[4]
  26. Pamela S. Engstrom, 18[4]
  27. Tom Brooks, 18[8]
  28. Christina E. Cadena Estabrook, 25, wife of Dean Estabrook, who was driving his own vehicle in front of the bus when the disaster occurred.[8] [9]

The crash claimed one additional victim. Daniel I. Wright, 15, died on May 24, 1976, at the Highland Hospital in Oakland, California due to the injuries he sustained in the crash.[6]


The accident was investigated by the National Transportation Safety Board, which it attributed to the unfamiliarity and inexperience of the driver with the design of the 26-year-old bus and his confusion of oil pressure and air pressure warnings.[10] Contributing to the accident were:

  1. The failure of the air compressor drivebelt
  2. The failure of the maintenance program and pre-trip inspection to detect and replace the deteriorated air compressor drivebelt
  3. The failure of the signing system to adequately alert the driver to the critical geometrics of the ramp
  4. The severe radius of the curvature of the ramp
  5. The design of the curb as part of the ramp railing
  6. A bridge rail system that did not redirect the bus.[10]

The upside of the accident is that the training and testing for school bus drivers has been improved, plus the design and construction of school buses has been improved. Additionally pre-trip and post-trip inspections and repairs are now more refined and more regulated.


The Yuba City bus disaster was the second-worst bus disaster in U.S. history, exceeded only by the 1963 train-bus collision in Chualar, California, which claimed the lives of 32 Mexican farmworkers.

In May 1996, on the twentieth anniversary of the accident, a memorial built near the water at the Martinez Marina was dedicated to the victims. Bearing the names of those who died, it was constructed by firefighters who had responded to the accident and their friends and largely funded by them and donations they obtained.[11] On the 35th anniversary of the accident in May 2011, Contra Costa County firefighters dedicated a monument in Yuba City.[12]

In 2015, the I-680 freeway off-ramp was replaced with one having a longer and flatter approach.[13]


  1. ^ a b c Erin Hallissy (1996-09-16). "20 Long Years Later, Martinez Remembers A School Bus Crash". San Francisco Chronicle. Retrieved 2013-11-19.
  2. ^ a b c Hager, Philip & Lembke, Daryl (May 22, 1976). "School bus crash kills 28". LA Times (via St. Petersburg Times).
  3. ^ a b c d "28 Killed in Calif. School Bus Crash". Pittsburgh Post-Gazette. AP. May 22, 1976.
  4. ^ a b c d e f g h i j k Blaylock, Bill. "Survivor: 28 Perished in Snap of a Finger." The Sacramento Bee, May 23, 1976, pg 5. https://www.newspapers.com/clip/112653146/yuba-city-highschool-bus-crash/
  5. ^ a b c d e f g h i j k "YCHS chois bus crash toll up to 29." The Gridley Herald. May 26, 1976, pg 1. https://www.newspapers.com/clip/112656061/yuba-city-bush-crash/
  6. ^ a b "Another bus crash victim dies as town begins burying dead." The San Bernardino County Sun, May 25, 1976, pg 16. https://www.newspapers.com/clip/112654728/yuba-city-bus-crash/
  7. ^ "A Week of Sadness: Yuba City Commemorates Losses." The Petaluma Argus-Courier. May 29, 1976, pg 5.
  8. ^ a b c "Casualty List Told." The Times. May 22, 1976, pg 2. https://www.newspapers.com/clip/112657510/yuba-city-bus-crash/
  9. ^ "'It was like a bad dream,' Bus Crash Survivor Says." The Petaluma Argus-Courier. May 22, 1976, pg 1-2. https://www.newspapers.com/clip/112658396/yuba-city-bus-crash/
  10. ^ a b "Accident Investigation - NTSB". National Transportation Safety Board. 1977-09-29. Retrieved 2013-11-19.
  11. ^ "The Worst Bus Crash in the Nation's History Happened 36 Years Ago in Martinez". Claycord.com. Retrieved 2013-11-19.
  12. ^ Gerardo Recinos (2013-05-26). "Firefighters pay homage to bus accident victims : Martinez News-Gazette". Martinezgazette.com. Retrieved 2013-11-19.
  13. ^ Laura Anthony (2015-05-21). "CALTRANS REPLACES DEADLY I-680 OFF-RAMP IN MARTINEZ : ABC & News". abc7news.com. Retrieved 2015-10-06.

38°01′28″N 122°06′40″W / 38.0244°N 122.1110°W / 38.0244; -122.1110