The secretary and Air Force Gen. Charles Q. Brown Jr., chairman, Joint Chiefs of Staff, host an observance ceremony at 9 a.m. EDT at the National 9/11 Pentagon Memorial in honor of the 184 people killed in the 2001 terrorist attack on the Pentagon. The ceremony, not open to the public, allows the family members of those lost in the terrorist attack to observe the memory of their loved ones. It will be livestreamed on Defense.gov and broadcast on Channel 2 in the Pentagon.