From NWS in Springfield MO:
Severe storms producing tornadoes affected Southwest Missouri (NWS Springfield County Warning Area) during the afternoon and evening of May 22, 2011. Large portions of Joplin Missouri were severely damaged. Results of damage assessed yielded a rating of an EF5 (greater than 200 mph).

Latest reports from Tuesday evening 5/24 indicate an estimated 122 fatalities and several hundred injured in the Joplin MO area. The Joplin tornado is the deadliest since modern recordkeeping began in 1950 and is ranked 8th among the deadliest tornadoes in U.S. history.

The tornado surpassed the June 8, 1953, tornado that claimed 116 lives in Flint, Mich., as the deadliest single tornado to strike the U.S. since modern tornado recordkeeping began in 1950. The deadliest tornado on record in the U.S. was on March 18, 1925. The “Tri-State Tornado” (MO, IL, IN) had a 291-mile path, was rated F5 based on a historic assessment, and caused 695 fatalities.

The US tornado death toll through the month of May this year is the highest since modern record keeping began in 1950. Also, 2011 is already ranked 8th among the deadliest tornado years in U.S. history.

This is the 4th EF5 tornado this year, the other 3 were during the April 27th outbreak in Mississippi and Alabama. This is the 56th EF5/F5 tornado since 1950.