Tornadoes are among the world's deadliest natural disasters. They have touched down on all of Earth's continents, except Antarctica. Tornadoes can kill people in their path, destroy homes and other buildings, and devastate the lives of people who survive these frightening storms. Most tornadoes take place in the United States. They usually happen during spring and summer. But they can occur anyplace, anytime. Part of The Earth's Worst Natural Disasters series, The Worst Tornadoes on Record explains how these devastating natural disasters form and discusses some of the worst storms in U.S. history.