Bob Hill, a heavy mobile equipment mechanic with the U.S. Army Corps of Engineers' Philadelphia District, surveys the tornado-stricken landscape of the city during a break in debris removal operations here July 24. Hill is one of more than 300 Corps employees who've volunteered to support federal recovery operations after an EF-5 tornado ripped through the city May 22. More than 8,000 commercial and residential buildings were damaged or destroyed, including St. John's Regional Medical Center, visible in the background. The Federal Emergency Management Agency tasked the Corps with removing debris from public rights of way and some residential properties, constructing temporary critical facilities such as schools and fire stations, and building temporary housing parks.