US Marks 25th Anniversary of 9/11 Attacks

The United States marked the 25th anniversary of the September 11, 2001 attacks on Friday with memorial ceremonies at the National September 11 Memorial in New York, the Pentagon and the Flight 93 National Memorial in Shanksville, Pennsylvania. The attacks, carried out by 19 al-Qaeda hijackers who seized four commercial airliners, killed 2,977 people and remain the deadliest terrorist attack in American history. This year's New York ceremony added a first-ever seventh moment of silence, honoring people who later died from illnesses linked to the toxic dust released when the Twin Towers collapsed. Previous commemorations featured six silences marking the moments the planes struck and the towers fell. More than 9,400 people have died from 9/11-related illnesses, according to the federal program established to provide medical care to those affected, though questions remain about the precise scale of dust-linked illness. The commemorations coincided with the release of roughly 170,000 pages of city documents concerning what officials knew about air toxicity after the attacks.