On Thursday, July 5th, 1973 at approximately 1:30 pm, two employees of Droxol Propane were in the process of off-loading the contents of the 127 kl (33,500 gal) 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. It is believed that the employee somehow generated a spark that ignited the leaking propane. Both of the employees were either knocked down or fell from the tank car. One of the employees was able to stumble across the street to the Highway Patrol Office to ask for help.
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 4 engines and a rescue vehicle. Station 2 was located just 800 m (.5 mi) west of the Droxol Gas Distribution Plant.
Kingman Firefighters received the first call for help at 1:57 pm and arrived on the scene three (3) minutes later. Knowing that they were not properly equipped to extinguish the fire, they attempted to keep the tank cool to avoid an explosion. Police officers from Kingman, officers from the Highway Patrol and deputies from the Sheriff’s Office began blocking the roads in an effort to control the gathering crowd. Members of the Fire Department were working to set up unmanned nozzles to increase the amount of water flowing onto the tank.
A large crowd of people had gathered across Route 66 with nothing more than about 185 m (200 yd) of desert separating them from the scene. Officers were ordering them to move back, while others were working to block traffic on the roadway and establish a perimeter around the scene. The explosion occurred approximately 20 minutes after the original call was received. Flames and debris were sent over 600 m (2000 ft) away. The 2-ton end cap of the tank was propelled down the railroad spur approximately 400 m (.25 mi). The explosion left a 3 m (10 ft) deep crater where the tank once stood. Flaming propane and debris rained down on spectators and buildings in the area.
Over 100 people received burns from the explosion, and eleven firefighters and one civilian died, either immediately or within days of the incident. Several buildings in the immediate area were ignited by the burning propane, causing further problems to the incident. Slurry bombers from the Bureau of Land Management, normally used to fight range fires, helicopters from the Highway Patrol, and helicopters from two air force bases joined in to fight the fires and help evacuate the injured. Over 100 casualties jammed the Mohave General Hospital, being transported by one ambulance, police cars, and private vehicles. The most severely burned victims were flown to hospitals in Phoenix about 282 km (175 mi) away or Las Vegas about 160 km
(100 mi) in the opposite direction.
The explosion shook this tiny town of 7,500 and was reportedly felt up to 8 km (5 mi) away.
Source: National Hazardous Materials Fusion Center