On this day in US history, the worst tornado to ever blow through the country became the deadliest on March 18, 1925. Rolling through Missouri, Indiana, and southern Illinois, 695 people were killed, along with 13,000 injured in the event, with many of the casualties happening in southern Illinois. The tornado traveled almost 219 miles and spent more than 3 hours on the ground, devastating 164 miles at a speed of 70 miles per hour.