Oklahoma City mayor says 12,000 to 13,000 homes damaged or destroyed by May 20 tornado - Article Photos 167/565

Oklahoma Baptist University students Patiance Villa and Alex Smith extend volunteer help to clean up damage from Sunday's tornado in the Woodlands and Pecan Valley area on Thursday, May 23, 2013 in Little Axe, Okla. Photo by Steve Sisney, The Oklahoman