WEST — Investigators working to figure out what caused a massive, deadly fertilizer plant explosion in Texas have talked to more than 370 people and received more than 200 tips as they continue to search for a breakthrough.
Two weeks after the April 17 blast that killed at least 14 people, agents compare their work to solving a puzzle or completing an archaeological dig.
“We’re trying to find the critical piece,” said Chris Connealy, the state fire marshal, on Thursday.
Their work is complex for several reasons: the magnitude of the blast at West Fertilizer, which knocked out windows and rooftops all over the tiny town of West and registered as a small earthquake; the deaths of 10 first responders and two others who volunteered to help; and the spread of debris as far as two miles away.
Agents are using digital mapping of the plant, rakes, shovels and front-end loaders to sift through dirt and rubble over an approximately 15-acre site. Possible bits of evidence are being cataloged and tested.
Investigators in dark blue uniforms and light blue helmets raked through piles of dirt and lifted debris. Many of them had worked almost every day since the blast. Small skid-steer loaders carried away piles of dirt that already had been examined.
On a cool, windy day, the faint smell of fertilizer filled the air, and officials said the air quality was continuously being monitored. Remnants of burned-out cars and trash littered the sides of the plant site.
Some of the remaining wall from a plant building had been raised at the site, as officials also are trying to reconstruct as much of the plant as possible as part of their investigation.
A specialist from the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives will later design a model of what the plant looked like at the time of the explosion, so that authorities can test several scenarios of what happened, said Assistant State Fire Marshal Kelly Kistner and Robert Champion, ATF’s Dallas special agent in charge.
Authorities have not yet begun to fully investigate the approximately 90-foot-wide crater left by the blast, Kistner said. On Thursday, teams were sifting through dirt at the former site of an administrative building next to the crater.
Chemical tests so far have only revealed fertilizer at the site, Kistner said.
He said he didn’t know yet what specific chemicals were found or how much ammonium nitrate was on site during the blast.
Officials would not reveal all of the technology they are using, but said the process could continue after a previously set May 10 target date. They also continue to investigate the possibility that the blast was a criminal act.