Tornado Damage In Moore, Oklahoma

Debris covers the ground after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

A vehicle lies upside down in the road after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Massive piles of debris cover the ground after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

People assess the damage after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Only the rubble of a house remains after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Nathan Ulepich searches outside of the back of his house, destroyed after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Dana Ulepich searches inside a room left standing at the back of her house, destroyed after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Dana Ulepich looks at the debris from her house, destroyed by a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Yvonne Barragar sits in front of her destroyed house after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Piles of debris lie around the north side of Plaza Towers Elementary School after it was damaged by a tornado May 21, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Damaged vehicles are piled up in front of the Warren Theater after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

People walk through a damaged area near the Warren Theater after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Yellow caution tape marks off the area surrounding the heavily damaged Moore Medical Center after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Flipped vehicles are piled up outside the heavily damaged Moore Medical Center after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

MOORE, OK- MAY 20: Flipped vehicles are piled up outside the heavily damaged Moore Medical Center after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. The tornado, reported to be at least EF4 strength and two miles wide, touched down in the Oklahoma City area on Monday killing at least 51 people. (Photo by Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Cars marked with an orange X, denoting they had been checked for occupants, are piled up in what was the front entrance to the damaged Moore Medical Center after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

Cars marked with an orange X, denoting they had been checked for occupants, are piled up in what was the front entrance to the damaged Moore Medical Center after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

The hood of car is wedged into the front window of the Moore Medical Center after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)

Tornado Damage In Moore, Oklahoma

A Goodwill donation station is surrounded by debris after a powerful tornado ripped through the area on May 20, 2013 in Moore, Oklahoma. (credit: Brett Deering/Getty Images)