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.

A sprawling storm system crossing the U.S. on Friday overturned semitrucks on highways and fanned wildfires in Texas and Oklahoma, where officials called for evacuations in at least one town. Tornado threats loomed for the Mississippi Valley into the night and the Deep South on Saturday.