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Senior Airman Gilberto Hernandez, 775th Civil Engineering Squadron, rings the bell during the 9/11 Memorial Ceremony Sept. 9, 2022, at Hill Air Force Base, Utah. The Sept. 11, 2001, attacks were one of the darkest days in U.S. history, with nearly 3,000 people killed. (U.S. Air Force photo by Cynthia Griggs)