About 12:12 a.m. P.s.t., on April 7, 1982, several vehicles on westbound California State Route 24 entered the north, No. 3 Bore of the Caldecott Tunnel near Oakland, California. A Honda car driven by an intoxicated driver struck the raised curbs inside the tunnel and came to rest at the left edge of the roadway about one-third of the way through the tunnel. It was struck soon afterward by a following gasoline tank truck and tank trailer and then by an AC Transit bus which subsequently struck the tank trailer. The busdriver was ejected, and the empty bus continued west, exited the tunnel, and struck a concrete road support pier. The tank trailer overturned and gasoline was spilled inside the tunnel. A fire erupted and heavy black smoke quickly filled the tunnel. The tank truck and tank trailer, the Honda car, and four other vehicles that had entered the tunnel were completely destroyed by the fire. Seven persons were killed, and two people were treated for minor smoke inhalation. The tunnel incurred major damage.

​We determined that the probable cause of this accident was a combination of events involving

1. the erratic driving by the intoxicated driver of a passenger vehicle which stopped in a through traffic lane creating a traffic obsitcle;
2. the inattention of the truckdriver causing his vehicle to strike the passenger vehicle; and
3. the busdriver's overtaking the truck too rapidly to enable him to avoid striking the passenger vehicle when it unexpectedly appeared in the path of his bus.

Contributing to the cause and the severity of the accident was the presence of a flammable cargo tank truck and cargo tank trailer in the tunnel and the damage to the overturned trailer which permitted a loss of flammmable cargo and a fire.

Also contributing to the severity of the accident and injuies were the lack of adequate monitoring capabilities and variable message signs or traffic signals at the entrance of the tunnel and within the tunnel, and the lack of a communication system betwen the tunnel personnel and tunnel occupants which if present, might have facilitated occupant evacuation.

​We made recommendations to

• the Director of the California Department of Transportation,
• the Secretary of the U.S. Department of Transportation,
• the Alameda/Contra Costa Transit District,
  
• the American Trucking Association,
• the American Public Transit Association, and
• Armour Oil Company.