Tony Gutierrez/AP
An aerial view shows homes damaged by Monday's tornado on May 21, 2013, in Moore, Okla.
Tony Gutierrez/AP
An aerial view of Monday's tornado path is seen May 21, 2013 in Moore, Okla. At least 24 people, including nine children, were killed in the massive tornado that flattened homes and a school in Moore, on Monday afternoon.
Tony Gutierrez/AP
An aerial view of an entire neighborhood destroyed by Monday's tornado is shown Tuesday, May 21, 2013, in Moore, Okla.
Tony Gutierrez/AP
An aerial view shows Briarwood Elementary with vehicles thrown about after Monday's tornado, May 21, 2013, in Moore, Okla.
Steve Gooch/AP
This aerial photo shows the remains of homes hit by a massive tornado in Moore, Okla., May 20, 2013.
Steve Gooch/AP
This aerial photo shows damage to Moore Medical Center after it was hit by a massive tornado in Moore, Okla., May 20, 2013.
Steve Gooch/AP
This aerial photo shows damage to Moore Medical Center after it was hit by a massive tornado in Moore, Okla., May 20, 2013.
Steve Gooch/AP
This aerial photo shows damage to Plaza Towers Elementary School after it was hit by a massive tornado in Moore, Okla., May 20, 2013.
Steve Gooch/AP
This aerial photo shows the remains of homes hit by a massive tornado in Moore, Okla., May 20, 2013.
Steve Gooch/AP
This aerial photo shows damage to Plaza Towers Elementary School after it was hit by a massive tornado in Moore, Okla., May 20, 2013.
Steve Gooch/AP
This aerial photo shows the remains of homes hit by a massive tornado in Moore, Okla., May 20, 2013.
Steve Gooch/AP
This aerial photo shows damage to Plaza Towers Elementary School after it was hit by a massive tornado in Moore, Okla., May 20, 2013.
Steve Gooch/AP
This aerial photo shows the remains of homes hit by a massive tornado in Moore, Okla., May 20, 2013.
Steve Gooch/AP
This aerial photo shows the remains of homes hit by a massive tornado in Moore, Okla., May 20, 2013.
Steve Gooch/AP
This aerial photo shows the remains of homes hit by a massive tornado in Moore, Okla., May 20, 2013.
Steve Gooch/AP
This aerial photo shows damage to buildings hit by a massive tornado in Moore, Okla., May 20, 2013.
Tony Gutierrez/AP
A aerial view shows Moore Medical Center, where a vehicle sits on the roof of the building following Monday's tornado, May 21, 2013, in Moore, Okla.