The threat of violent tornadoes in parts of the U.S. proved deadly as well as destructive as whipping winds moved east into the Mississippi Valley and

At least 12 fatalities have been reported in Missouri, according to the Missouri State Emergency Management Agency. The deaths come as a massive storm system moving across the country unleashed winds that damaged buildings, whipped up deadly dust storms and fanned more than 100 wildfires.

Numerous significant tornadoes are expected Saturday afternoon and evening, with the highest risk across several states in the Deep South, forecasters say.

"Get to the sturdiest structure you have access to and remain in place until the storms pass," the NWS told residents in Alabama on Saturday night, when multiple tornado warnings were issued. At least 250,