(From left) Airman 1st Class Austin Layton, Airman 1st Class Shane Kobzina, and Senior Airman William Olson, 28th Operations Support Squadron air traffic controllers, visually scan the airfield for safety risks in the ATC tower on Ellsworth Air Force Base, S.D. April 3, 2012. Scanning the runway helps prevent vehicles, people and any animals from jeopardizing airfield safety. (U.S. Air Force photo by Airman 1st Class Kate Thornton/Released)