Gotta to the “Tri-State Tornado” killed 695 people and injured 2,027, traveling more than 300 miles through Missouri, Illinois and Indiana on March 18, 1925. It was rated an F5 at the top of the old Fujita scale (with winds of 260-plus mph).
I mentioned the Tri-State too, but I used slightly different stats, but that is beause the stats differ slightly based on the reference source. Some in 1925 believed more than 1,000 died. It was hard to get an accurate death count because it traveled over such a large area. Plus, there were places so utterly destroyed it was impossible to know if some of the people were blown away or if they left after the storm to look for work elsewhere. Some of the injured people were hastily put on trains and they never returned home. Because of inefficient communication, chaos, and the tremendous area involved, it was simply impossible to get precise figures.