Service members salute the American flag while the Star Spangled Banner is played, at the 9/11 event at Joint Base Langley-Eustis, Va., Sept. 9, 2016. The event honored the 15th anniversary of 9/11 terrorist attacks. (U.S. Air Force photo by Airman 1st Class Tristan Biese)

U.S. Air Force Tech. Sgt. John Rattay, Heritage of America Band bugler, plays taps during a ceremony in remembrance of the firefighters who sacrificed their lives to save others during 9/11 at Joint Base Langley-Eustis, Va., Sept. 9, 2016. Taps is played to honor military and public service members who died in the line of duty. (U.S. Air Force photo by Airman 1st Class Tristan Biese)

Firefighters from the 733rd Civil Engineer Division and the Hampton Fire Department raise the American flag between two firetrucks at Joint Base Langley-Eustis, Va., Sept. 9, 2016. The American flag was raised in remembrance of the fallen firefighters during the tragic event of 9/11. (U.S. Air Force photo by Airman 1st Class Tristan Biese)

Firefighters from the 733rd Civil Engineer Division perform a detail in honor of the 9/11 ceremony at Joint Base Langley-Eustis, Va., Sept. 9, 2016. The ceremony was held to honor those whom lost their lives during the tragic event that happened on Sept. 11, 2001. (U.S. Air Force photo by Airman 1st Class Tristan Biese)

Participants at the 9/ 11 event finished the ceremony with a 5k at Joint Base Langley-Eustis, Va., Sept. 9, 2016. They ran to support and honor the public service members who paid the ultimate price on Sept. 11, 2001. (U.S. Air Force photo by Airman 1st Class Tristan Biese)

U.S. Air Force Senior Airman Brit Beshear, 733rd Civil Engineer Division driver operator, rings a bell to honor the fallen firefighters of 9/11 during a ceremony at Joint Base Langley-Eustis, Va., Sept. 9, 2016. The ringing of the bell signifies a firefighter’s last call to duty and was rung a total of nine times. (U.S. Air Force photo by Airman 1st Class Tristan Biese)