Costliest tornado

The costliest single tornado in history was the Joplin Tornado, which struck the city of Joplin, Missouri, USA, on 22 May 2011. The EF5 tornado killed 161 people and caused an estimated $2.8 billion of insured losses and as much as $3.18 billion in damages overall (when uninsured losses are factored in).

Joplin is a city in south-western Missouri, close to the state's border with Arkansas (to the south) and Kansas and Oklahoma (to the west). At the time of the 2011 tornado outbreak, it had a population of around 50,000 people spread over an area of roughly 81 km2 (31 sq mi). Most of the land within the city limits was covered by residential neighbourhoods of timber-framed single-family homes.

Joplin is located on the eastern edge of the Great Plains and "Tornado Alley" – the region of the central USA where cold, dry air from the Rocky Mountains mixes with warm, wet air from the Gulf of Mexico, creating powerful thunderstorms and tornadoes. According to US National Weather Service (NWS) records, 182 tornadoes rated EF2 or higher touched town within an 80-mi (128-km) radius of Joplin between 1950 and 2011, though no major tornadoes had passed within the city limits since 1971.

The NWS regional office in Springfield, Missouri, issued a tornado watch for Joplin and surrounding communities at 3 p.m. on Sunday 11 May 2011, warning that a supercell thunderstorm was forming in the area. At around 5 p.m. this was upgraded to a tornado warning, and the town activated its emergency sirens shortly afterward. The tornado was spotted on the outskirts of the city at 5.34 p.m., and reached the built-up area a few minutes later.

The tornado touched down as an EF1, with wind speeds of 80–100 mph (130–160 km/h), but quickly intensified. As it passed through Joplin's western suburbs it strengthened to EF3, gathering enough power to flip cars and tear the roofs off timber-framed houses. The first fatality occurred at this time, a person killed when their car was flipped as the tornado crossed Schifferdecker Avenue. By 5.38 p.m., just four minutes after it was first sighted, the tornado had reached EF4 and was now throwing cars, obliterating any wooden structures in its path and tearing apart steel-framed commercial buildings as it moved towards Joplin's more built-up areas.

By this time the tornado was generating wind speeds of around 200 mph (320 km/h), powerful enough to rip the concrete foundations of smaller buildings out of the ground. It swept past the St. John's Regional Medical Center, a modern reinforced concrete hospital building, deforming the structure so badly that it would later have to be demolished (this accounted for $600 million of the total insured losses). It passed through the centre of Joplin, crossing Main Street and razing many large, sturdy structures including schools, churches and apartment buildings down to the foundations.

The tornado ended its path across Joplin at around 5.58 p.m., passing through the city's eastern suburbs and into the sparsely populated farmland beyond. It had crossed the city from west to east, a distance of 6.2 mi (10 km), in 20 minutes, destroying or damaging buildings within an area of 10.5 sq mi (27.1 km2) – around a third of the city.

A total of 7,500 homes in Joplin sustained significant damage, including 3,000 that were either totally demolished or damaged beyond economic repair. In addition 553 businesses and civic buildings were destroyed. Of the 161 deaths, the majority occurred inside buildings that collapsed or were swept away. Due to its location on the edge of Tornado Alley, and a local belief that the city was protected in some way by local geography, very few homes or businesses had basements or storm shelters.