Lm Otero / LM Otero/AP
An investigator pauses while sifting through the debris of the destroyed fertilizer plant in West, Texas, Thursday, May 2, 2013.
DALLAS — Investigators will announce on Thursday the results of a probe into what caused last month's fertilizer plant explosion in West, Texas, that killed 14 people and obliterated sections of the small town, a state agency said on Tuesday.
The State Fire Marshal's Office and the Bureau of Alcohol, Tobacco, Firearms and Explosives will release the findings of their joint investigation at a news conference, according to a news release from the fire marshal's office.
Texas officials on Friday announced a criminal investigation into the blast.
Investigators confirmed a week ago that ammonium nitrate stored at the West Fertilizer Co detonated in the April 17 explosion. The cause of the fire and subsequent blast at the facility, which also injured around 200 people, is expected to be announced by officials on Thursday.
More than 70 investigators have developed more than 200 leads, from which more than 400 interviews have been conducted, investigators said last week.
Investigators believe the fire started somewhere in the 12,000-square-foot fertilizer and seed building.
Looking into the cause of the initial fire, they have eliminated the weather, natural causes, anhydrous ammonia, a railcar containing ammonium nitrate, and a fire within the ammonium nitrate bin.
Additionally, they said water used during fire-fighting activities did not contribute to the cause of the explosion as some had speculated.
Bryce Reed, a Texas paramedic who was among the first responders at the explosion site, was arrested last week for possession of pipe bomb components. State officials have said no evidence linked Reed's arrest to the plant disaster.
Reed is expected to plead not guilty in federal court on Wednesday, his lawyer said.