Violent tornadoes ripped through parts of the U.S., wiping out schools and toppling semitractor-trailers in several states, part of a monster storm that killed at least 18 people as more severe weather was expected late Saturday.

At least five people have been killed in a monster storm sweeping across much of the U.S. At least two people were killed in Missouri after a tornado struck the Bakersfield area.

The threat of tornadoes moved east into the Mississippi Valley and Deep South on Saturday, a day after a massive storm system moving across the country unleashed winds that damaged buildings, whipped up deadly dust storms and fanned more than 100 wildfires.

Severe weather has been blamed for the deaths of over a dozen people, a number that could grow with the inclusion of wildfire and traffic deaths. More than 8.6 million people, mostly in Louisiana,

"The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and several tornadoes," National Weather Service warns