Runners take off at the start of the Run for the Fallen event on Sept. 10, 2016 at Travis Air Force Base, Calif. The Run for the Fallen was a 3.43 mile run organized by the 60th and 349th Civil Engineer Squadrons to honor the 343 firefighters who lost their lives on Sept. 11, 2001. (U.S. Air Force photo by Senior Airman Shelby R. Horn/Released)