But as the atmosphere swirled above, catastrophe brewed. Late in the afternoon, a tornado rated as the most intense on the Enhanced Fujita (EF) Scale, an EF5, cut a 6-mile-long (9.7-kilometer) gash through the densely populated Joplin metro area, home to more than 50,000 people. Despite the city’s track record of following the latest building codes and residents receiving several warnings beforehand, the tornado — with winds estimated at more than 200 miles (321 kilometers) per hour at times — killed 161, injured over 1,000 and wrecked more than 8,000 buildings, including a major hospital and other critical facilities. The high number of fatalities made it the deadliest single tornado in the U.S. since the National Weather Service (NWS) began official record-keeping in 1950. And the $2.8 billion in damages made it the costliest.