Dennis Fink and Thomas Frisbie, Computer Sciences Corporation contractors, secure boards in front of doors and windows at the Precision Measurement Equipment Laboratory during a hurricane exercise April 24, 2013, at Keesler Air Force Base, Miss. Throughout the exercise, "Hurricane Hana" brought severe thunderstorms, F2 tornado strength winds, rain and hail damage to several base facilities. The purpose of the exercise was to prepare Keesler for the upcoming hurricane season. (U.S. Air Force photo by Kemberly Groue/Released)