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.
Mercy (healthcare organization)
On May 22, 2011, one of Mercy's larger hospitals, St. John's Regional Medical Center (now rebuilt and called Mercy Hospital Joplin) was seriously damaged by a tornado from the May 2011 tornado outbreak. At least four people were killed inside the hospital and its grounds, and surviving patients were evacuated from the health facility, which sustained major structural damage. One of the hospital's towers took a direct hit by the storm and was rotated four inches on its foundation.