U.S. mourns thousands lost, killed in world's worst terrorist attack

WASHINGTON - President Joe Biden is commemorating the 20th anniversary of September 11, 2001, on Saturday with three somber, silent events as he visits the three sites of the worst terrorist attack in modern history.

Biden, along with first lady Jill Biden, is attending ceremonies at the places where four planes and 19 hijackers started America's 20-year involvement in Afghanistan. His first stop, in New York Ci