Emergency communication system
161 people were killed and at least 990 injured when an EF5 multiple-vortex tornado hit Joplin, Missouri. Because Joplin is located in a tornado-heavy area of the country, many people considered the tornado sirens routine and ignored them. Instead, many residents waited until they received confirmation from another, non-routine, source, such as seeing the tornado, a radio or TV report, or hearing a second siren. In the aftermath, an assessment team recommended that emergency warnings take risk perception into account to convey a sense of urgency. NOAA Officials are considering ways to change the warning system to distinguish smaller tornadoes from more deadly ones.
Tornado outbreak sequence of May 21–26, 2011
On May 22, a large, devastating EF5 tornado tracked through Joplin, Missouri, leaving behind catastrophic damage. It was a multiple-vortex tornado in excess of wide. Mainly the southern part of the city was affected with most structures in the area either damaged or destroyed. 162 people were killed along the path through Jasper and Newton counties in Missouri, making it the deadliest U.S. tornado since 1947, and one of the deadliest single tornadoes ever recorded. Among the most heavily damaged structures was St. John's Hospital (pictured right), which later was torn down due to the severity of the structural damage. Damages were estimated at around $2.8 billion (2011 USD).