Hundreds of people from across the country gathered near the World Trade Center to commemorate the thousands of lives lost on 9/11.
The nation is commemorating the 12th anniversary of the 2001 attacks which resulted in the deaths of nearly 3,000 people after two hijacked planes crashed into the World Trade Center, one into the Pentagon in Arlington, Virginia and one crash landed in Shanksville, Pennsylvania.
On Wednesday at 8:46 a.m., the time when terrorists crashed American Airlines Flight 11 into the north tower of the World Trade Center in New York City, hundreds gathered at the site where the towers collapsed.
President Barack Obama, joined by Vice President Joe Biden and first lady Michelle Obama, paid tribute on the lawn of the White House and later observed a moment of silence at the Pentagon.
"Our hearts still ache for the futures snatched away, the lives that might have been," Mr. Obama said at a memorial service at the Pentagon, where 184 people died in the attacks. To those who survived, he said: "Your lives are the greatest tribute to those that we lost: for their legacy shines on in you."
"In your resilience you've taught us all there's no trouble that we cannot endure, there's no calamity we cannot overcome," the president said.
A moment of silence was also held at the U.S. Capitol. Numerous ceremonies and events will be held in the Washington area to commemorate the 12th anniversary of the 9/11 attacks.