Tornadoes can strike with little or no warning. Most injuries happen when flying objects hit people. Experts say the best place to be is in an underground shelter, or a small, windowless room in the lowest part of a building.

A car sits in a drainage ditch in Colerain, North Carolina, after a tornado ripped through the area Saturday

People driving during a tornado are told to find low ground and lay flat, facedown, with their hands covering their head. People in the path of a tornado often just have minutes to make life-or-death decisions.

BOB DOUGHTY: The deadliest American tornado on record was the Tri-State Tornado of March eighteenth, nineteen twenty-five. It tore across Missouri, Illinois and Indiana. About seven hundred people were killed.

A "tornado outbreak" is often defined as six or more tornadoes produced by the same weather system within a day. But the outbreak of April third and fourth, nineteen seventy-four, set a national record. It is remembered as the "Super Outbreak." One hundred forty-eight tornadoes struck during a twenty-four-hour period. More than three hundred people were killed and nearly six thousand others injured.

One tornado that was especially destructive hit Xenia, Ohio. The sound you are about to hear comes from the website www.xeniatornado.com. It is one man's recording of the tornado moving closer.

(SOUND)

KATHERINE COLE: No two tornadoes look exactly the same. And no two tornadoes act the same way.