The Kingman BLEVE: 40 Years Later

Today marks the 40th anniversary of the Kingman Explosion, also known as the Doxol Disaster–a catastrophic boiling liquid expanding vapor explosion (BLEVE) that occurred on July 5, 1973, in Kingman, Ariz. Eleven firefighters were killed in the incident:

–    William L. Casson
–    Myron B. Cox
–    Roger A. Hubka
–    Joseph M. Chambers III
–    Marvin E. Mast
–    Arthur C. Stringer
–    Christopher G. Sanders
–    Richard Lee Williams
–    Frank S. Henry
–    John O. Campbell
–    Donald G. Webb
–    Alan Hansen

According to the National Hazardous Materials Fusion Center, at approximately 1:30 pm, two employees of Droxol Propane were in the process of off-loading the contents of a railroad tank car into two propane storage tanks. When the valves were opened, one of the connections was discovered to be leaking. One of the employees attempted to stop the leak, somehow generating a spark that ignited the leaking propane. According to reports, the initial fire badly burned the two railroad employees present, one of whom later died from his burns.

Kingman firefighters received the first call for help at 1:57 p.m., and arrived on the scene three minutes later. In 1973, the Kingman Fire Department was a combination of 6 career firefighters and 36 volunteers operating out of two stations. Equipment in service at the time consisted of four engines and a rescue vehicle. Station 2 was located a half-mile west of the Droxol Gas Distribution Plant.

Firefighters attempted to keep the tank cool to avoid an explosion, and worked to set up non-staffed nozzles to increase the amount of water flowing onto the tank.

According to Wikipedia, the burning propane gas escaping from the valve connection on the rail car quickly heated the liquid propane inside, increasing the tank pressure. This in turn increased the leak and fire, further heating the tank car. Within minutes of the initial fire, the safety valve on the car opened from the dangerously increased pressure in the tank car. The stream of propane gas blowing out of the safety valve immediately ignited as well.

At this point, two burning streams of propane were shooting out of the car, one horizontal from the transfer valve, and one vertical from the safety valve. The heat from the streams of burning propane continued to heat the tank, increasing pressure to dangerous levels.

According to the National Hazardous Materials Fusion Center, the BLEVE occurred approximately 20 minutes after the original call was received. Flames and debris were launched more than 2,000 feet away. The explosion left a 10-foot-deep crater where the tank once stood.

Flaming propane and debris rained down on spectators and buildings in the area. More than 100 people received burns from the explosion. Eleven firefighters and one civilian died, either immediately or within days of the incident.

Planes from the Bureau of Land Management dropped fire retardant, and helicopters from the Highway Patrol and from two Air Force bases joined in to fight the fires and help evacuate the injured.

The explosion shook this tiny town of 7,500 and was reportedly felt up to 5 miles away. Prior to the Yarnell wildfire of 2013, the Kingman incident was the worst firefighting disaster in Arizona history.

For more information about BLEVE incidents, check out Fire Engineering’s article “BLEVE: Facts, Risk Factors, and Fallacies.”