Alabama was in the path of the most destruction from Wednesday's storms. Authorities on Friday raised the number of confirmed dead to 228. More than 30 lost their lives in Tuscaloosa, which is home to the University of Alabama. Two students are among the dead.
In March 1932, 332 people died, all in Alabama.
In April 1974, a series of twisters killed 315 people in 11 states.
The largest death toll ever in the U.S. from twisters was on March 18, 1925 when 747 people were killed in storms that raged through Missouri, Illinois and Indiana. In that outbreak, a single, 219-mile-long tornado killed 695 people.