Tornadoes have killed at least 19 people across the southern and midwestern United States.
Rescue workers leave the parking lot of the Enterprise High School in Alabama after checking for victims in the vehicles
Eight teenagers died when a tornado struck Enterprise High School in Alabama, blowing out the walls and collapsing part of the roof.
"Enterprise has suffered major and widespread damage," said Governor Bob Riley, who declared a state of emergency and sent 100 National Guard troops to the town.
He said rescue workers were still moving debris to search for survivors as night fell.
In Georgia, storms that swept through the southwestern part of the state killed at least three people and caused an unknown number of injuries, the Georgia Emergency Management Agency said.
In the Missouri town of Caulfield, a tornado killed a girl in a mobile home.
Alabama state officials sent rescue teams, ambulances, generators and emergency lights to Enterprise to aid the search for survivors. Phone service and electricity were out through much of the area.
In Chicago, more than 400 flights were cancelled at O'Hare International Airport as storms and fog rolled in.