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

A huge storm system crossing the U.S. threatens to unleash tornadoes Friday in the Mississippi Valley, blizzards in the northern Plains and dry, gusty conditions in Texas and Oklahoma that pose a high risk of wildfires.