The explosion occurred during a propane transfer from a Doxol railroad car to a storage tank on the Getz rail siding near Andy Devine Avenue/Route 66. The incident began when a hair line crack in the side of the tanker was leaking non smelling gas that was ignited by static electricity this caused a spark that ignited the leaking propane gas, this was discovered after a long investigation and trial was conducted. The initial fire badly burned the two railroad employees present, one of whom later died from his burns. 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.
The Kingman Fire Department responded, and began setting up attack lines to cool the propane 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.
The fire department was in the process of setting up a deluge gun to cool the car, which would have delivered far more water than the booster attack lines they initially were using; however, before the deluge gun could be made ready, the pressure inside the tank car reached the design bursting limit and the tank car exploded. Almost instantaneously, thousands of gallons of boiling liquid propane flashed to gas with the drop in pressure and simultaneously ignited. The resulting explosion produced a shock wave that was heard and felt for over 5 miles, and a fireball over 1,000 feet in diameter. Burning propane rained down on everything in the vicinity, and the remnants of the rail car were propelled over a quarter mile from the explosion site. The three firefighters closest to the explosion were killed instantly; eight more died from their burns shortly thereafter. In addition to the eleven city firefighters and one railroad worker killed in the disaster, one state trooper was also killed in the explosion. Over 90 onlookers gathered on the highway were burned or injured, some badly. The most severely burned, including some of the firefighters, were airlifted to hospitals in Las Vegas and Phoenix. This incident was the worst firefighter tragedy in Arizona until 2013 when 19 Granite Mountain Hotshots firefighters were killed in the Yarnell Hill Fire.
The incident was photographed in detail by a photographer on the roof of his home near the explosion site, and reportedly also was captured on 8mm film by a vacationing family. Because of this documentation, this explosion has become a classic incident studied in fire department training programs worldwide. The Arizona State Archives in Phoenix has 24 cubic feet (680 L) of original material, including civil case material and photographs, concerning the "Kingman Explosion." The incident was chronicled in the July 1993 issue of American Fire Journal in an article titled "Kingman Revisited".
- "The Disaster Story". Kingman Historic District. Retrieved 1 July 2013.