Hundreds of relatives of those killed in the September 11, 2001, terrorist attacks in the United States gathered in New York City to commemorate the 14th anniversary of tragedy.
In the somber September 11 ceremony, families at the former site of the World Trade Center observed a moment of silence and read the names of the nearly 3,000 people who died when Al-Qaeda terrorists hijacked and crashed four passenger airliners.
In Washington, U.S. President Barack Obama and first lady Michelle Obama stepped out of the White House to observe a moment of silence at 8:46 a.m. — when the first plane hit the north tower.
Two of the planes crashed into the World Trade Center; one crashed into the Pentagon outside Washington; and the fourth crashed in a field in Pennsylvania after passengers overpowered the terrorists.
The former site of the World Trade Center is now a memorial plaza and museum. Mourners at the September 11 ceremony stood at the empty footprint of the fallen towers, which were toppled by the two hijacked airliners 14 years ago that morning.
Ringing bells marked the moments when each of the four planes crashed, and when the towers fell.
Obama was scheduled to observe the anniversary later in the day at Fort Meade, Maryland, in recognition of the U.S. military's work in protecting the country.