Violent tornadoes ripped through parts of the U.S., wiping out schools and toppling semitractor-trailers in several states.

The threat of tornadoes is moving east into the Mississippi Valley and Deep South a day after a massive storm system moving across the country unleashed winds that damaged buildings, whipped up dust storms that caused deadly crashes and fanned more

The dynamic storm from Friday through Sunday earned an unusual “high risk” designation from weather forecasters.