High Quality Content by WIKIPEDIA articles! The Super Outbreak is the largest tornado outbreak on record for a single 24-hour period. From April 3 to April 4, 1974, there were 148 tornadoes confirmed in 13 US states, including Illinois, Indiana, Michigan, Ohio, Kentucky, Tennessee, Alabama, Mississippi, Georgia, North Carolina, Virginia, West Virginia, and New York; and the Canadian province of Ontario. It extensively damaged approximately 900 square miles (1,440 square kilomete (more…)