WEST, Texas - Rescuers searched the smoking remnants of a Texas farm town Thursday for survivors of a thunderous fertilizer plant explosion, gingerly checking smashed houses and apartments for anyone still trapped in debris while the community awaited word on the number of dead.
Initial reports put the fatalities as high as 15, but later in the day authorities backed away from any estimate and refused to elaborate. More than 160 people were hurt.
A breathtaking band of destruction extended for blocks around the West Fertilizer Co. in the small community of West. The blast shook the ground with the strength of a small earthquake and crumpled dozens of homes, an apartment complex, a school and a nursing home.
Police Sgt. William Patrick Swanton in Waco, to the south, described ongoing search-and-rescue efforts as "tedious and time-consuming," noting that crews had to shore up much of the wreckage before going in.
There was no indication the blast, which sent up a mushroom-shaped plume of smoke and left behind a crater, was anything but an industrial accident, he said.
The explosion was apparently touched off by a fire, but there was no indication what sparked the blaze. The company had been cited by regulators for what appeared to be minor safety and permitting violations over the past decade.
The Wednesday-night explosion rained burning embers and debris on terrified residents. The landscape Thursday was wrapped in acrid smoke and strewn with the shattered remains of buildings, furniture and personal belongings.
While the community tended to its deep wounds, investigators awaited clearance to enter the blast zone for clues to what set off the plant's huge stockpile of volatile chemicals.
"It's still too hot to get in there," said Franceska Perot, a spokeswoman for the Bureau of Alcohol, Tobacco, Firearms and Explosives, adding later that she wasn't sure when her team would be able to start its investigation.
The precise death toll was uncertain. Three to five volunteer firefighters initially were believed to be among the dead, which authorities said could number as many as 15. But the state Department of Public Safety said later that the number of fatalities couldn't be confirmed.
Gov. Rick Perry called the explosion "a truly nightmare scenario for the community" and said he had been in touch with President Obama, who promised his administration's assistance.
Authorities said the plant handles the fertilizers anhydrous ammonia and ammonium nitrate, the latter of which was used in the 1995 Oklahoma City bombing and several other attacks, such as the first bombing attempt at the World Trade Center in 1993.
Neil Donahue, professor of chemistry at Carnegie Mellon University, said ammonium nitrate is stable, but if its components are heated enough they break apart in a runaway explosive chemical reaction.
"That happens almost instantaneously, and that's what gives the tremendous force of the explosion."
On StarNet: See more photos from the Texas fertilizer plant explosion on azstarnet.com/gallery