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.
Tornado preparedness
There were no building codes requiring tornado shelters nor specifically designed to prevent tornado damage until the 2011 Joplin tornado prompted a local ordinance requiring hurricane ties or similar fasteners. The state of Oklahoma adopted the minimum U.S. standard that year for the first time, but did not add high-wind protections like those in Florida designed to protect against hurricanes. Other states in Tornado Alley have no statewide building codes. The chance of any given location in Tornado Alley getting hit by an F-2 tornado (strong enough to do major structural damage and exceeding the 90 mph guideline for straightline winds) is about 1 every 4,000-5,000 years; in other areas the annual probability is one in several million. The most stringent building codes only require earthquake strengthening for a 1 in every 500-1,000 year probability.