Airman 1st Class Patrick Garrett, 28th Civil Engineer Squadron electrical technician, picks up a rock during a foreign object and debris walk on Ellsworth Air Force Base, S.D., March 12, 2012. Even the smallest rock or piece of wire left on the flightline can potentially cause millions of dollars worth of damage to aircraft engines. (U.S. Air Force photo by Airman 1st Class Alystria Maurer/Released)