in April 1974, the 2nd-largest tornado outbreak ever in a 24-hour period
The Super Outbreak was an outbreak of violent tornadoes in April 1974. It involved many states in the US, including Ohio, Illinois, Indiana, Mississippi and North Carolina. The incident involved less than thirty F4 or F5 tornadoes that happened on April 3rd and 4th, and killed 319 people. Seven of these were at the F5 level on the United States Fujita scale. Xenia, Ohio was among the hardest hit cities.