Violent tornadoes ripped through parts of the U.S., wiping out schools and toppling semitractor-trailers in several states.

Millions of Americans across the country are on alert for a severe weather outbreak as violent, long-track tornadoes with damaging winds of up to 80 mph and large hail are expected across the Midwest and South with the cross-country storm moveing east.

Thousands of FirstEnergy and REA Energy Cooperative customers were put in the dark as severe storms ripped through west-central Pennsylvania Sunday afternoon, triggering a tornado warning shortly after 1 p.

An "outbreak" of tornadoes and severe thunderstorms is expected through Saturday night in Alabama, Mississippi, Louisiana, and other southern states.

The National Weather Service has confirmed at least four tornado touchdowns occurred in the Chicago area during a severe weather outbreak Friday.