ATLANTA Tornadoes swept across the southern United States and killed at least 20 people in three states, ripping up a hospital and high school where students huddled for shelter, authorities said on Friday.
Nine were killed in Georgia, where a hospital was hit late on Thursday, and 10 in two southern Alabama towns, officials said.
The storms also took the life of a young girl in Missouri, they said.
In Georgia, two were killed in the town of Americus when the Sumter Regional Hospital was hit by an apparent tornado, and six died in hard-hit Baker County. The ninth fatality was in Taylor County, a bit north of Americus, said state emergency management official Michael Parker.
In the Missouri town of Caulfield, a tornado killed a girl in a mobile home, damaging six other homes and two gasoline stations, officials said on Thursday.
Tara Emnett, an official at the Enterprise mayor's office in Alabama, told Reuters that all but one of the victims there were students at the high school, a shredded building left surrounded by broken trees and overturned cars.
Another fatality in Enterprise occurred in a residence, Emnett said. Emergency management officials, meanwhile, confirmed at least one storm-related death elsewhere in Alabama, in Wilcox County.
The students at the high school had been assembled in the hallways when the storm hit, in line with emergency procedures, said Coffee County Emergency Management director John Tallas, whose area of responsibility includes Enterprise.
"They were in the hallway of the school which typically is the most structurally sound part of the building," Tallas told CBS television's "Early Show."
He did not elaborate, but students interviewed on the program said the hallway's roof caved in soon after they gathered there.
"I just sat down. The next thing I knew windows and stuff were busting everywhere," student Robert Humphrey said.
Doctors at Medical Center Enterprise treated more than 50 people for lacerations, broken bones and other injuries, hospital chief executive Jeff Brannon said. Most were hurt at the school.
Hospital workers had rushed to move patients away from the windows as sirens screamed out a warning moments before a dark funnel cloud roared past. Hospital windows burst and cars were pummeled in the hospital parking lot, Brannon said.
Thursday's storms came just a month after a tornado killed about 20 people in central Florida.
The height of the tornado season in the United States does not begin until May, but winter tornadoes are common in years which experience the El Nino phenomenon -- an unusual warming of Pacific waters that can bring torrential rain to some parts of the globe and extreme drought to others.
(Additional reporting by Verna Gates in Birmingham, Ala.)