A 9/11 memorial float including a section of a steel I-beam from one of the Twin Towers led the procession of Airmen and first responders participating in the 9/11 Remembrance Ruck March on Ellsworth Air Force Base, S.D., Sept. 8, 2012. Nearly 150 Ellsworth Airmen, family members and friends teamed up with area police officers, firefighters and other first responders for the 11-mile rucksack march to commemorate the 11th anniversary of 9/11. (U.S. Air Force photo by Airman 1st Class Kate Thornton-Maurer)