Rescue workers dig through the rubble of a collapsed wall at the Plaza Tower Elementary School to free trapped students in Moore, Okla., following a tornado Monday, May 20, 2013. (AP Photo Sue ... more 
Rescue workers dig through the rubble of a collapsed wall at the Plaza Tower Elementary School to free trapped students in Moore, Okla., following a tornado Monday, May 20, 2013. (AP Photo Sue Ogrocki) less 
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Associated Press
Tue, May 21, 2013 3:47 AM EDT