Americans are marking 24 years since the Sept. 11, 2001, attacks with solemn ceremonies, volunteer work and other tributes honoring the victims. At the Pentagon in Virginia, a memorial service honored the 184 service members and civilians killed. A large U.S. flag unfurled outside a building of the Pentagon as U.S. National Anthem is sung and Amazing Grace is played on bagpipes At the World Trade Center site in New York City, the nearly 3,000 victims’ names are expected to be read aloud. And near Shanksville, Pennsylvania, a similar ceremony honors the victims of Flight 93. On Sept. 11, 2001, nearly 3,000 people were killed as 19 al-Qaida hijackers seized control of four jetliners, sending two of the planes into New York’s World Trade Center, one into the Pentagon in Arlington, Virginia, and the fourth into a field in western Pennsylvania. It remains the deadliest terror attack in history.