The most destructive tornado outbreak of the 20th century was the "Super Outbreak" of April 3-4, 1974. During a 16-hour period, 148 tornadoes hit 13 states, including Indiana. The path of destruction stretched 2,500 miles. More than 300 people died and more than 5,000 were injured. The most notable tornado in this group destroyed much of Xenia, Ohio. In Indiana, 21 tornadoes struck 39 counties, killing 47 people. For more information, click here.