An American flag flutters on a young tree stripped of bark after a massive tornado passed through the town killing at least 116 people May 24, 2011 in Joplin, Missouri. The tornado that ripped through the town of about 50,000 people May 22, is being called the deadliest single tornado in the U.S. in 60 years. (Photo by Julie Denesha/Getty Images)

Destroyed homes and debris cover the ground as a second storm moves in on May 23, 2011 in Joplin, Missouri. A powerful tornado ripped through the densely populated town of Joplin yesterday killing at least 122 people. (Photo by Julie Denesha/Getty Images)

Sheila Bolte (L) and Ashley Hailey look up at the American flag they placed in a tree branch over the remains of Ashley's home after a tornado on May 23, 2011 in Joplin, Missouri. (Photo by Julie Denesha/Getty Images)

A freight train waits to pass through Joplin after a massive tornado passed through the town killing at least 122 people on May 24, 2011 in Joplin, Missouri. (Photo by Mario Tama/Getty Images)

Damage is seen one day after a tornado tore through Joplin killing at least 122 people on May 24, 2011 in Joplin, Missouri. (Photo by Benjamin Krain/Getty Images)

Armored car courier Josh Beck works on salvaging cash from an ATM which was damaged and tossed approximately 20 feet when a massive tornado passed through the town killing at least 122 people on May 24, 2011 in Joplin, Missouri. (Photo by Mario Tama/Getty Images)