190911-N-HV737-1047 DIEGO GARCIA, British Indian Ocean Territory (Sept. 11, 2019) U.S and British flags are flown at half-mast at U.S. Navy Support Facility (NSF) Diego Garcia, Sept. 11, 2019 marking the 18th anniversary of the Sept. 11, 2001 terrorist attacks on the World Trade Center, Pentagon and United Airlines Flight 93. NSF Diego Garcia provides logistic, service, recreational and administrative support to U.S. and Allied Forces forward deployed to the Indian Ocean and Arabian Gulf. (U.S. Navy photo by Mass Communication Specialist 2nd Class Charlotte C. Oliver /Released)