They are most common in the Central Plains and southeastern US, but they have been reported in all 50 states, according to the National Weather Service. Tornadoes kill an average of 60 people a year in the United States, according to the National Oceanic and Atmospheric Administration. Here are the 10 deadliest tornadoes to touch down in the United States, according to figures from NOAA1. The "Natchez Tornado" killed 317 people and injured 109 on May 6, 1840, along the Mississippi River in Louisiana and Mississippi. The "St. Louis Tornado" killed 255 people and injured 1,000 on May 27, 1896, in Missouri and Illinois.

Source: CNN May 23, 2019 14:37 UTC