Photo gallery: September 11, 2001
A fiery blast rocks the south tower of the World Trade Center as the hijacked United Airlines Flight 175 from Boston crashes into the building Sept. 11, 2001, in New York City.
(Spencer Platt / Getty Images)
(Richard Drew / Associated Press)
(Spencer Platt / Getty Images)
(Amy Sancetta / Associated Press)
(Doug Mills / Associated Press)
(Stan Honda / AFP-Getty Image)
(Mario Tama / Getty Images)
People flee the scene near New York’s World Trade Center after terrorists crashed two planes into the twin towers on Sept. 11, 2001.
(Diane Bondareff / Associated Press)
(Marty Lederhandler / Associated Press)
Two women hold each other as they watch the World Trade Center burn after a terrorist attack on the twin skyscrapers in New York on Sept. 11, 2001.
(Ernesto Mora / Associated Press)
People run from the collapse of the World Trade Center in New York on Sept. 11, 2001.
(Suzanne Plunkett / Associated Press) Pedestrians can be seen crossing the
Firefighters and emergency personnel look through the debris of United Airlines Flight 93 after it crashed on the morning of Sept. 11, 2001 near Shanksville, Pa. 40 victims were killed in the crash after passengers reportedly stormed the cockpit to thwart terrorists’ plans to use that plane as a weapon like the others. (David Maxwell, AFP/Getty)