9/11 Tower Challenge
Lt. Gen. Chris Nowland, 12th Air Force (Air Forces Southern) commander, speaks to participants about patriotism during the 9/11 Tower Challenge at the University of Arizona football stadium in Tucson, Ariz., Sept. 11, 2015. The 9/11 Tower Challenge was held to honor those who lost their lives during the Sept. 11, 2001 attacks and to show their support first responders and military members who continue to protect the U.S. from foreign and domestic threats. During the 9/11 Tower Challenge, participants climbed 2,071 steps representing the number of steps that were in the Twin Towers. (U.S. Air Force Photo by Tech. Sgt. Heather R. Redman/Released)