DALLAS — A fire that was intentionally set caused the 2013 explosion at a Texas fertilizer plant that killed 15 people, federal officials said Wednesday, describing the blaze as "a criminal act."
Federal and state investigators said no arrests have been made, but that authorities were investigating who may have set the fire inside the West Fertilizer Co. on April 17, 2013. The fire caused ammonium nitrate to ignite, triggering a massive explosion that also injured hundreds of people and left part of the small town of West in ruins.
Alcohol, Tobacco, Firearms and Explosives special agent Robert Elder said investigators came to their conclusion after ruling out other causes. He didn't release specifics or a possible motive, though inspectors previously said three possible scenarios caused the fire: faulty electrical wiring, a short circuit in a golf cart stored at the plant, or arson.
"We have eliminated all reasonable accidental and natural causes," Elder said during a news conference. "This was a criminal act."
The ATF also released a statement saying investigators determined the fire was "intentionally set" after investigators conducted more than 400 interviews, a fire-scene examination, reviewed witness photos and videos, and conducted "extensive scientific testing" at an ATF fire research laboratory.
A message left with West Mayor Tommy Muska was not immediately returned Wednesday afternoon.
The blast — one of Texas' worst industrial disasters — left a crater 90 feet wide and at least 10 feet deep in West, a town about 75 miles south of Dallas. All but three of the people killed were emergency personnel, primarily those from the West Volunteer Fire Department who responded to the initial blaze.
Federal regulators determined that factors contributing to the deadly explosion included careless storage of potentially explosive materials and lack of ventilation, along with inadequate emergency response coordination and training, such as hazardous materials training. Regulators also cited poor development planning that allowed homes and a school to be built nearby.
The U.S. Chemical Safety Board later adopted recommendations — which it doesn't have power to enforce — that federal regulators set higher standards for safe handling and storage of fertilizer-grade ammonium nitrate.
The lack of uniform regulations worries Mary Sanders, whose son, Kevin, was a volunteer firefighter killed in the explosion. She noted that Texas has taken steps to prevent a similar incident, including ensuring ammonium nitrate be kept separate from combustible material, but that regulations vary by state.
"All of those corrections are not going to be federally mandated," Sanders, who lives in suburban Chicago, said Wednesday.
The Chemical Safety Board's report, which the panel approved in January, noted that Texas had 80 plants that stored more than 5 tons of ammonium nitrate, a chemical used in fertilizer, and that 19 plants storing fertilizer-grade ammonium nitrate operated within a half-mile of a school, hospital or nursing home.
The West plant "was about 550 feet from the closest school, which sustained catastrophic damage as a result of the explosion, which could have resulted in additional loss of life had the school been in session at the time," the report noted. That explosion caused about $100 million in property damage, according to the Texas Department of Insurance, and insurance-related losses were approximately $230 million.
After the blast, a West paramedic was accused of collecting materials for an explosive device. Bryce Reed pleaded guilty to federal charges and served time in prison, though authorities never blamed him for the plant explosion. On Wednesday, Elder said Reed wasn't a suspect in the ongoing investigation.
Reed's stepfather, Gary Nelson, said he and his wife were in tears after hearing the fire was ruled arson. They're concerned they might have "to live through this mess again," he said. "It's awful."
Associated Press writer Betsy Blaney in Lubbock, Texas, contributed to this report.