On July 5, 1973, workers at the Doxol Gas Distribution Plant in Kingman, Arizona, began what should have been a routine job: transferring propane gas from a railway car into storage tanks. A series of small events and errors, however, snowballed into a massive tragedy that is still used as a warning in training material for industrial workers and fire departments across the country, and led to changes in industrial regulations.

Tank Car #38214, filled with 33,000 gallons of propane, was left sitting out in the hot sun in a railway yard until its contents could be transferred to storage. When two workers arrived to do that in the early afternoon, they quickly discovered that the tank was leaking through a faulty fitting. One of the workers attempted to tighten the fitting by hitting it with a wrench, creating a spark that ignited the escaping gas. Flames began shooting out of the tank, badly burning the two men. One of the workers managed to flee from the railway yard and got the attention of a police officer, who alerted the fire department of the growing fire.

Members of the Kingman Volunteer Fire Department quickly arrived to the scene and realized they were not equipped to handle the situation. Nevertheless, they tried to do what they could. They knew it would be impossible to put out the propane fire with water from their engine, but they could use their water to attempt to cool down the exterior of the tank and hopefully prevent it from losing structural integrity and exploding. The firefighters got to work preparing their pumps and hoses. Meanwhile, news of the event over local radio stations had attracted a crowd to watch the events unfold along the shoulder of a nearby highway, only 200 yards away. Police were in the process of installing roadblocks and attempting to get the onlookers to disperse when, at 2:10 p.m., the tank exploded.

The fireball from the explosion was over 1,000 feet in diameter. Burning propane and railway debris rained down over a quarter mile away. The explosion left a 10-foot-deep crater in the ground and the shockwave was felt five miles away. The Doxol Gas building, a tire shop, a restaurant, and a truck stop caught on fire in the blast. Three of the firefighters died instantly and eight others died in hospitals later. More than 100 other onlookers, police officers, and railway workers were injured. The Bureau of Land Management scrambled to get their tanker planes to combat several wildfires that were started by the explosion.

The Kingman Explosion led to changes in regulations on how flammable and explosive materials were transported and stored. Fire departments began using footage of the disaster in more extensive training for how to handle Boiling Liquid Expanding Vapor Explosions, or BLEVEs. Today, a memorial to the victims of the Kingman Explosion is the centerpiece of Firefighter’s Memorial Park, a public park in the city.