(AP Photo/Charlie Riedel)

Brittany Brown rushes to get aid after finding her grandmother''s cat "Kitty" which was buried in tornado rubble for two days at the grandmother''s destroyed home Wednesday, May 22, 2013, in Moore...

Brittany Brown rushes to get aid after finding her grandmother''s cat "Kitty" which was buried in tornado rubble for two days at the grandmother''s destroyed home Wednesday, May 22, 2013, in Moore, Okla. Cleanup continues two days after a huge tornado roared through the Oklahoma City suburb, flattening a wide swath of homes and businesses.

(AP Photo/Charlie Riedel)

Jesse Edgar takes a break in the shade while helping salvage items at a friend''s home Wednesday, May 22, 2013, in Moore, Okla. Cleanup continues two days after a huge tornado roared through the...

Jesse Edgar takes a break in the shade while helping salvage items at a friend''s home Wednesday, May 22, 2013, in Moore, Okla. Cleanup continues two days after a huge tornado roared through the Oklahoma City suburb, flattening a wide swath of homes and businesses.

(AP Photo/Charlie Riedel)

An unidentified man tosses a board as residents sort through their tornado-ravaged homes Wednesday, May 22, 2013, in Moore, Okla. Cleanup continues two days after a huge tornado roared through the...

An unidentified man tosses a board as residents sort through their tornado-ravaged homes Wednesday, May 22, 2013, in Moore, Okla. Cleanup continues two days after a huge tornado roared through the Oklahoma City suburb, flattening a wide swath of homes and businesses.

(AP Photo/Charlie Riedel)

An unidentified man tosses debris as residents sort through their tornado-ravaged homes Wednesday, May 22, 2013, in Moore, Okla. Cleanup continues two days after a huge tornado roared through the...

An unidentified man tosses debris as residents sort through their tornado-ravaged homes Wednesday, May 22, 2013, in Moore, Okla. Cleanup continues two days after a huge tornado roared through the Oklahoma City suburb, flattening a wide swath of homes and businesses.

(AP Photo/Charlie Riedel)

Cody Cannon looks at tornado destruction in his neighborhood from the second floor of his parent''s home that once was his bedroom Wednesday, May 22, 2013, in Moore, Okla. Cleanup continues two days...

Cody Cannon looks at tornado destruction in his neighborhood from the second floor of his parent''s home that once was his bedroom Wednesday, May 22, 2013, in Moore, Okla. Cleanup continues two days after a huge tornado roared through the Oklahoma City suburb, flattening a wide swath of homes and businesses.