WEST (May 16, 2013)—The State Fire Marshal's Office and Bureau of Alcohol, Tobacco, Firearms and Explosives have identified three possible causes of the fire that caused the deadly April 17 fertilizer plant explosion in West, two accidental and the third intentional, officials said during a late afternoon news conference Thursday.
Assistant State Fire Marshal Kelly Kistner addressing reporters Thursday in West. (Photo by Kyle Muscarello)
Investigators determined that the fire that led to the powerful explosion was caused either by a battery-powered golf cart that was kept in the fertilizer and seed building in which the fire started, the building’s 120-volt electrical system or by an intentional criminal act, said Robert Champion, special agent in charge of the Dallas office of the ATF.
Investigators recovered only a brake pad and an axle from the golf cart, which was not enough to allow them to determine whether the cart’s battery could have ignited the fire, but officials said there’s precedent for that happening.
Investigators determined the fire was not caused by spontaneous ignition, an earlier fire, a problem with the plant’s 480-volt electrical system that powered heavy equipment, anhydrous ammonia, ammonium nitrate, smoking or the weather, Champion said.
The investigators, who briefed local officials and met with the families of explosion victims earlier in the afternoon, said the tragedy unfolded in just 19 minutes.
West firefighters were dispatched to the plant at 7:32 p.m. on April 17, arrived at 7:38 p.m. and requested assistance from other departments at 7:41 p.m., Assistant State Fire Marshal Kelly Kistner said.
The plant exploded at 7:51 p.m., he said.
As much as 64 tons of ammonium nitrate was stored in the building, 28 to 34 tons of which exploded, Kistner said.
An additional 20 to 30 tons in the building and another 100 tons in a nearby railcar did not explode, he said.
The total amount of ammonium nitrate on the site was about 150 tons, less than 270 tons that federal records indicated was stored at the plant.
By comparison, the amount of ammonium nitrate that exploded on April 17 in West was about 12 times the amount used in the truck bomb that blew the side off of the Albert P. Murrah federal building on April 19, 1995 in Oklahoma City.
The fire actually caused two explosions, just milliseconds apart, Kistner said.
The first, which was the result of some combination of heat, building pressure from containment and shock from falling debris and equipment, triggered the second larger blast, he said.
Twelve first responders died in the explosion.
The blast, which left a crater 93 feet across and 10 feet deep, scattered debris over a 3,000-foot radius and one piece of evidence was found two-and-a-half miles from the blast site, Kistner said.
The officials emphasized Thursday that the investigation is ongoing and that only the work at the site of the explosion has been completed.
"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,” State Fire Marshal Chris Connealy said.
Additionally, the Texas Department of Insurance is responsible for the investigation of the line-of-duty deaths of the 12 first responders, the results of which likely won’t be available for several months, Kistner said.
Last Friday, the Department of Public Safety announced that DPS Director Steven McCraw had directed the Texas Rangers to join the McLennan County Sheriff’s Office in launching a criminal investigation of the blast.
"The citizens of McLennan County and Texas must have confidence that this incident has been looked at from every angle and professionally handled - they deserve nothing less," McLennan County Sheriff Parnell McNamara said in the statement issued by the DPS.
Gov. Rick Perry issued a statement Thursday evening expressing his appreciation to the investigators.
“While the cause of the fire remains undetermined and the investigation continues, this tragedy has shown the world the definition of compassion, from volunteer firefighters across the state rushing to help their colleagues at the scene, to friends, neighbors and Texans stepping in to help those who lost so much in the blast,” he said.
Texas U.S. Sens. John Cornyn and Ted Cruz issued a joint statement thanking the investigators.
“Our prayers remain with those struggling to recover and mourning the loss of loved ones. While the cause remains undetermined, it is our sincere hope that at the end of the investigation, the residents of West can find closure and begin to heal,” they said.