The cause of the fire that triggered the explosions in a fertilizer plant in Texas last month has been deemed “undetermined,” investigators say.
Texas State Fire Marshall Chris Connealy said the scene investigation into what caused the fire in the April 17 West Fertilizer Co. in West, Texas, is concluded. However, “while the scene examination has been completed, the investigation will remain open for purposes of conducting additional interviews, following up on leads, and the like,” Connealy added.
There are four official classifications of fire determinations: natural, accidental, incendiary and undetermined, Connealy said during a May 16 press conference in West. The cause of a fire may be ruled undetermined if it “cannot be proven to an acceptable level of certainty … or if multiple causes could not be eliminated,” he said.
Investigators found that rekindling of an earlier fire, spontaneous ignition, a 480 volt electrical system on the site, anhydrous ammonia, ammonium nitrate, smoking and weather were not responsible for starting the fire in the fertilizer and seed building.
There were, however, three things that could not be eliminated as causes of the fire, said Robert Champion, with the Dallas Field Office of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF).
Those are: the 120 volt electrical system in building where the fire started; a golf cart that was housed in the building, and an intentionally set fire, Champion said.
Champion said the golf cart could not be ruled out as the cause of the fire because only two pieces of it have been found: a break pad and an axle.
Some golf carts, he said, have batteries that have been known to start fires. Because they don’t have enough information about the golf cart in the fertilizer plant it cannot be eliminated as a source of the combustion.
The fire touched off two explosions in the fertilizer and seed building that occurred “within milliseconds” of each other, the investigators said. Fifteen people were killed in the fire and resulting explosions, Connealy said.
The blast opened a crater 93 feet wide and 10 feet deep, and property damaged occurred over a 37 block area. The furthest piece of evidence was found two and a half miles away.
It has been estimated that insured losses will reach $100 million.
Connealy said that in addition to investigators from the SFMO and the ATF, personnel from as many as 28-plus agencies have been working on “one common goal to understand what happened.”
While the scene investigation is concluded, other probes are continuing, Connealy said, including an inquiry into the line of duty deaths of the 12 responders. That investigation will likely take several months.
Neither Connealy nor Champion would comment on the scope of other continuing investigations, including the criminal investigation that was launched on May 10.