The nation paused Wednesday to remember the worst terrorist attack in U.S. history. It's been 12 years since nearly 3,000 people died in a series of suicide attacks on Sept. 11, 2001.
There were several ceremonies throughout the day to mark the date. The program at the National September 11th Memorial in Lower Manhattan included several moments of silence along with the reading of the names of the victims.
There was also a wreath laying and moment of silence at the Pentagon, where 125 people were killed when American Flight 77 crashed into it.
In Shanksville, Pennsylvania, the site of the crash of United Flight 93, there was also an observance. Passengers on the flight fought against the hijackers before it could reach any targets.