Sept. 11, 2017 Air Force senior leaders join Mattis, Dunford honoring Pentagon’s fallen, survivors, families 16 years after 9/11 During a Pentagon remembrance today on the 16th anniversary of the 9/11 terrorist attacks, Air Force senior leaders joined Defense Secretary Jim Mattis and Chairman of the Joint Chiefs of Staff Marine Corps Gen. Joe Dunford to honor those who died, the survivors and the families left behind.