In a press conference, Texas Department of Public Safety Sgt. Jason Reyes confirmed "with a heavy heart" that 12 bodies had been pulled from the area of the plant explosion.
Officials have said at least 150 homes had been destroyed. They have searched all but 25 homes for bodies and expect to finish the task by on Saturday.
At least three rescue trucks and one fire truck were also destroyed, an indication of how many firefighters had rushed to the scene Wednesday to fight the fire that was burning in the fertilizer facility.
"This is still being treated as a crime scene," he said.
Five West firefighters, one Dallas firefighter and four emergency responders were killed, the State Firemen's and Fire Marshals' Association of Texas said in a statement yesterday.
Despite coming to the terms, the residents of this small town, with a population of 2800, are perplexed and dumbfound for answers. The blast stunned residents and left behind a trail of charred devastation in the small town.
The fertilizer plant explosion leveled buildings, ripped up walls and threw people on the ground blocks away.
About half the town was evacuated, including a nursing home with 133 residents. It was still unclear what the exact number of casualties was.
Officials are treading cautiously on providing specific numbers on victims, but fire officials confirmed some deaths among their crew.
Federal and state investigators were awaiting clearance to enter the blast area to search for clues to the cause of both the initial fire and explosions.
"It's still too hot to get in there," Federal Bureau of Alcohol, Tobacco, Firearms and Explosives spokeswoman Franceska Perot said.
There was no indication of foul play. With destruction so vast, it was well into Thursday before officials could comprehend and then describe the scope of the tragedy.
Texas Gov Rick Perry, declaring the town a disaster area, said the earthquake-like explosion will likely affect every citizen of this tightly knit community of some 2,500 people located just off Interstate 35.
He said President Obama called him from Air Force One en route to Boston on Thursday to offer federal assistance.
While the cause of the blast is not clear, ammonium nitrate used in many such farm applications is explosive and often used to build deadly roadside bombs in Afghanistan.
Swanton said there were no indications the blast was anything other than an industrial accident.
"It is a very volatile material," says David Small, spokesman for the Pentagon's task force to counter improvised explosive devices, called IEDs.
Fertilizer is made from nitrogen, phosphate and potassium, and she notes that the manufacturing of nitrogen carries great safety concerns.