Officials at the U.S. Centers for Disease Control and Prevention in Atlanta said the nation's third-deadliest tornado disaster occurred in the U.S. Southeast from April 25-28, 2011.
"Individuals who work or live in a tornado-prone area should develop a tornado safety plan prior to severe weather," CDC officials advised.
Among the 338 fatalities, the median age was 55, the age range was 4 days to 97 years, approximately one-third were older adults, 46.7 percent were in single-family homes and 26.6 percent were in mobile homes.
Overall, 57.7 percent of the decedents were female, and 32.5 percent were age 65 or older, with 84 percent deceased white, the report said.
The leading cause of death was traumatic injury, including 21.9 percent with head injuries.
The National Weather Service forecast the storm system five days in advance and issued numerous tornado watches with a mean lead time of 2.4 hours, and warnings with a mean lead time of 22 minutes.
"The public, especially older adults and residents of mobile/manufactured homes, should pre-identify an accessible safe room, prepare the room with personal protection items such as blankets and helmets and monitor local weather for tornado warnings," CDC officials suggested.
The findings were published in the CDC's Morbidity and Mortality Weekly Report.
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