A monstrous tornado at least half a mile wide roared through the suburbs of Oklahoma City leaving a trail of destruction in its wake.
The fierce winds, reaching speeds of up to 200mph, destroyed Plaza Towers Elementary School in the suburb of Moore, killing a number of children.
The storm tore off the roof, knocked down walls and turned the playground into a mass of twisted plastic and metal.
The Moore Medical Centre was evacuated after it was severely damaged by the twister.
Glenn Lewis, the mayor of Moore, told NBC News: "The whole city looks like a debris field. It looks like we have lost our hospital. I drove by there a while ago and it's pretty much destroyed."
Briarwood Elementary, also in Moore, stood in the storm's path and was badly damaged as it ripped through the state.
Sections of walls were left peeled away, giving clear views into the building, while in other areas cars hurled by the storm winds were lodged in the walls.
At least 24 people, including seven children, are thought to have been killed by the tornado as emergency crews continue to desperately search the wreckage for further survivors.