2011 Joplin tornado
Overall, the tornado killed 158 people (with an additional three indirect deaths), injured some 1,150 others, and caused damages amounting to a total of $2.8 billion. It was the deadliest tornado to strike the United States since the 1947 Glazier–Higgins–Woodward tornadoes, and the seventh-deadliest overall.
1953 Worcester tornado
However, the Worcester tornado's greatest effect on the nation was its being the principal catalyst for the Storm Prediction Center's reorganization on June 17, 1953, and subsequent implementation of a nationwide radar/storm spotter system. The results proved successful: since June 9, 1953, no single U.S. tornado had killed over 100 people until the Joplin, Missouri tornado of May 22, 2011.