A fertilizer explosion that killed 15 people and injured dozens in West, Texas, in April 2013 was intentionally set, government officials said during a press conference Wednesday.
"The fire has been ruled as incendiary; this means this fire was a criminal act," said Rob Elder, special agent in charge of the Bureau of Alcohol, Tobacco, Firearms and Explosives' Houston Field Division.
The fire originated in the West Fertilizer Company's fertilizer seed building, Elder said. He declined to elaborate on the source of ignition or if any accelerant was used, citing the open investigation.
The fire and eventual explosion covered a 37-square-block area, destroyed more than 500 homes and left a crater 93 feet wide and 12 feet deep at the site of the blast. Items of evidence were recovered as far away as 2.5 miles, Elder said.
He said Wednesday officials "hypothesized, considered, tested and eliminated" all "reasonable, accidental and natural fire scenarios" before drawing their conclusion.
Bryce Reed, a paramedic for West EMS who helped evacuate residents before the blast, was found to be in possession of bomb-making materials in the days after the explosion. Investigators, however, found no evidence linking him to the fertilizer blast. After undergoing a psychiatric evaluation, Reed was sentenced to 21 months in prison in the unrelated pipe bomb case.
Elder reiterated Wednesday that Reed is not a suspect in the West explosion.
"He pled guilty to charges. He did his time and, to my knowledge, he served his time and is back out. We do not consider him a suspect in this case," Elder said.
The U.S. Chemical Safety Board and the state fire marshal's office previously issued reports faulting the storage of the fertilizer, emergency response and other factors in contributing to the blast, which registered as an earthquake of magnitude 2.1.
Elder said the investigation into the ammonium nitrate explosion is one of the largest fire investigations ever undertaken by the ATF. Investigators have spent more than $2 million so far, some of which went to fund the scale reproduction of a portion of the West Fertilizer Co. plant to try to determine exactly what took place.
The families of the victims from the fertilizer plant explosion were called to a meeting by federal investigators Wednesday morning to hear the news that the fire and explosion that killed their loved ones was not an accident.
"It was a total surprise," said Phil Calvin. "They talk about terrorism a lot of different ways. To me, it's just, it's terrorism."
Calvin's son, Perry Calvin, a volunteer firefighter, rushed to try and extinguish the fire but was killed in the blast.
"To think someone could have done that intentionally," Phil Calvin said, shaking his head. "It was like somebody just hit me in the face. It hurt, and the longer I thought about it the madder I got."
Perry Calvin was one of the 15 people who died in the explosion, 12 of them firefighters just like him.
"I mean, whoever it was, I hope they catch them and put them in a place where I never have to see them," Phil Calvin said. "Ever."
Throughout the investigation, officials conducted more than 400 interviews, completed a fire scene examination, reviewed video and performed extensive scientific testing at the ATF Fire Research Lab in Maryland.
Elder added a full report on the blast will not be released until the conclusion of the criminal case and that murder charges, if any, would be determined after an arrest is made.
A recent investigation by The Dallas Morning News found stockpiles of ammonium nitrate are still stored near schools, houses, nursing homes and even a hospital in eight Texas communities more than three years after the deadly blast.
Elder said the ATF was offering a reward of up to $50,000 for information that leads to the arrest and prosecution of the person or people responsible for the explosion and fire. The Waco-McLennan County Crime Stoppers program is offering a separate $2,000 reward for the same information.
Those with information are asked to call 254-753-4357 or submit tips online at www.wacocrimestoppers.org. All tips received will be forwarded to the ATF for follow-up.