Skip Ribbon Commands
Skip to main content
Bookmark and Share this page

Accident Report Detail

Southern Pacific Transportation Co., Freight Train 2nd BSM 22 Munitions Explosion

Executive Summary

On May 24, 1973, Southern Pacific Transportation Company's freight train 2nd BSM 22, was approaching Benson, Arizona, when 1 of 12 munitions boxcars in the train's consist caught fire. The boxcars were loaded with 500-lb MK 82 bombs. As the train stopped, the cargo exploded, and the explosions continued for several hours.

Probable Cause

The National Transportation Safety Board determines that the probable cause of the accident was the exposure of heat-sensitive bombs in Car 38 to a fire inside the car. The fire most likely originated from sparks off the brakeshoes which ignited the sodium nitrate impregnated floorboards.

Accident Location: Benson , AZ    
Accident Date: 5/24/1973
Accident ID: 79783

Date Adopted: 2/26/1975
NTSB Number: RAR-75-02
NTIS Number: PB-241580/AS

Related Report

Related Press Releases

Related Events

Related Investigations