A massive storm system that brought tornadoes, rain, high winds and wildfires killed dozens of people in the Midwest and South over the weekend.

At least 30 people died as violent weather swept the country on Friday and Saturday, and the threat isn't over.

"The scale of devastation across our state is staggering," Missouri Gov. Mike Kehoe said. "While we grieve the lives of those lost, we are also focused on action."

Violent tornadoes ripped through parts of the U.S., wiping out schools and toppling semitractor-trailers, part of a monster storm that has killed at least 40 people across six states.

In some extreme cases, thunderstorms can spawn a derecho, a long-lived windstorm with gusts over 100 mph, strong enough to cause widespread destruction. If a severe thunderstorm warning mentions damaging winds or a derecho, take cover immediately—just as you would for a tornado.

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

The number of fatalities increased after the Kansas Highway Patrol reported eight people died in a highway pileup caused by a dust storm Friday in Sherman County. At least 50 vehi