180807-M-TR039-002 SHANKSVILLE, Pa. (Aug. 7, 2018) Americans paused to remember the Sept. 11, 2001, terror attacks which killed nearly 3,000 people in New York, Virginia, and a field in western Pennsylvania. The Tower of Voices, located in Shanksville, Pa., is a monument constructed by the National Park Service to pay homage to those who died aboard Flight 93. Unveiled Sept. 9, 2018, the 93-foot tall structure made of concrete and steel, features 40 chimes, one for each of the passengers killed in the crash. (Photo courtesy of the National Park Service/Released)