Missouri
Located in Tornado Alley, Missouri also receives extreme weather in the form of severe thunderstorms and tornadoes. The most recent tornado in the state to cause damage and casualties was the 2011 Joplin tornado, which destroyed roughly one-third of the city of Joplin. The tornado caused an estimated $1–3 billion in damages, killed 159 (+1 non-tornadic), and injured over 1,000 people. It was the first EF5 to hit the state since 1957 and the deadliest in the U.S. since 1947, making it the seventh deadliest tornado in American history and 27th deadliest in the world. St. Louis and its suburbs also have a history of experiencing particularly severe tornadoes, the most recent memorable one being an EF4 tornado that damaged Lambert-St. Louis International Airport on April 22, 2011. One of the worst tornadoes in American history struck St. Louis on May 27, 1896, killing at least 255 and causing $10 mil. damage ($3.9 bil. damage in 2009) or $ in today's dollars.
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.