The deadliest tornado in recorded U.S. history occurred 100 years ago. The Tri-State Tornado touched down in southeastern Missouri on March 18, 1925.

At least 19 people have died as an outbreak of tornadoes ravished through the South and Midwest early Saturday morning, leaving a path of destruction in their wake.

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 moving east.