A massive explosion has ripped through a fertiliser plant in West, Texas, possibly leaving 60-70 people dead including first responders.
Many more people are injured, with reports the explosion 'levelled' buildings in a five-block radius, including a school and a nursing home.
Officials have confirmed two people are dead, but the toll is expected to rise. A local medical official has told CNN the toll may hit 60-70 people.
Department of Public Safety spokesman D.L. Wilson said the damage is immense.
"We have a tremendous amount of injuries, propably over 100 injuries at this time, we do have confirmed fatalities," he said.
"The number is not current yet, it could go up by the minute. We're in there searching the area right now.
"Fire fighters trying to be safe. Wind blowing, still smoking, small flames, they don't want to get fire fighters hurt or injured inside blast area."
Mr Wilson said the area surrounding the blast was a disaster zone.
"I can tell you I was there, I walked through blast area, massive. Just like Iraq, like Murray Building in Oklahoma city, so you can imagine what kind of damage we're looking at.
"50- 75 houses damaged, apartment complex with 50 units, completely skeleton in there," he told reporters.
Firefighters responding to the scene in West were also injured in a secondary blast, according to radio traffic by emergency managers being broadcast by CBS News.
"There has been an explosion on the fire scene, there are firefighters down at this time," a dispatcher said.
A man on the scene reported that "the restroom is severely damaged we have many people down."
A triage site which has been treating hundreds of residents, including the elderly from a nearby nursing home, has now been moved amid fears a second silo may explode.
An official from a local hospital told CNN at least 60 patients have arrived for treatment following the explosion and many of the injuries are 'very serious'.
There have been unconfirmed reports that several people, including children and the elderly are trapped in buildings in the area surrounding the plant.
Hundreds of emergency services vehicles are on the scene with emergency workers from surrounding counties called in to help with the rescue effort.
Authorities are reportedly going door-to-door to check on residents.
The explosion reportedly blew windows out of buildings several miles away.
“My husband and I were cleaning up the kitchen after supper, and heard what we thought was someone running into our house. It shook our windows and doors. We immediately ran outside looking for the worst,” one witness told KWTX News.
Another witness, Gulf war veteran Paul L. Manigrasso told KWTX he felt the blast in Waxahachie.
“Based on my Naval experience...we knew immediately what it was, but cannot believe it occurred 40 miles away,” he said.
"It was a small fire and then water got sprayed the ammonia nitrate, and it exploded just like the Oklahoma City bomb," Jason Shelton, a clerk at the Czech Best Western Hotel in West, told The Dallas Morning News.
"I live about a 300 metres from it and it blew my screen door off and my back windows. There's houses levelled that were right next to it.”
Bill Bohannan, who was visiting his parents in West, near the plant, witnessed the explosion.
"It knocked us into the car ... Every house within about four blocks is blown apart," he told the Waco Tribune-Herald.Crystal Anthony told the paper that a nearby nursing home, apartment complex and West Middle School had also caught fire. Anthony said she and her daughter were almost knocked down several blocks from the explosion.