HIGHWAY ACCIDENT REPORT
Adopted: May 5, 1976
SURTICAS, S.A., TANK-SEMITRAILER OVERTURN,
EXPLOSION, AND FIRE
NEAR EAGLE PASS, TEXAS
APRIL 29, 1975 
NTSB Number: HAR-76/04
NTIS Number: PB-254034/AS 

SYNOPSIS

At 4:20 p.m. on April 29, 1975, a Surtigas, S.A., tractor-tank-semitrailer, westbound on U.S. Route 277 near Eagle Pass, Texas, swerved to avoid an automobile ahead which was slowing for a turn. The tank-semitrailer separated from the tractor, struck a concrete headwall, and ruptured; vaporized LPG was released. The ensuing fire and explosion destroyed a building and 51 vehicles. The 51 persons who were in the area were burned and 16 persons, including the truckdriver, were killed.
The National Transportation Safety Board determines that the probable cause of this accident was the evasive action taken by the truckdriver to avoid a slowing vehicle in his path of travel. The cause of the fatalities and injuries to persons in the vicinity was the explosive force and fire, from which they had no time to escape. The rapid development of the explosive force and fire was caused by the gross rupture of the tank.

RECOMMENDATIONS

As a result of its investigation of this accident, the National Transportation Safety Board made the following recommendations:

to the Federal Highway Administration:

"Promulgate a regulation to require the criteria established in the Handbook of Highway Design for Operating Practices (E2 Culverts and Bridge Structures) be mandatory for all modified and new designs.

"Compile and evaluate accident data related to unprotected, raised concrete headwalls and sidewalls which, because of their location, are roadside fixed objects, to determine whether added emphasis for their modification or protection is warranted."
to the Texas State Department of Highways and Public Transportation:

"Conduct an engineering survey on U.S. Route 277 between the intersection with U.S. Route 57 and the city limits of Eagle Pass to determine if a prohibition of parking on the shoulder of this high-speed highway or a reduction in the speed limit, or both, would reduce the traffic conflicts in this area; then, take appropriate actions in accordance with the findings of the survey."

to the U.S. Department of Transportation:

"Initiate a research program to identify new approaches to reduce the injuries and damages caused by the dangerous behavior of pressurized, liquefied flammable gases released from breached tanks on bulk transport vehicles."

"Establish a regulation to require the safety registration statements authorized by Section 106(b) of the Hazardous Materials Act of persons transportation bulk shipments of pressurized, liquefied petroleum gases in a form and quantity capable of causing widespread injury and property damage in transportation accidents."