President Obama, with his wife Michelle, accompanied by Vice President Joe Biden and a number of White House staff lead the country in marking the 13th anniversary of the 9/11 attacks as they emerged from the white house a few minutes before 9 am ET to observe a moment of silence at the South Lawn of the White House.
After a moment of silence they heard the playing of Taps then proceeded to the Pentagon for the commemoration service where Stephen Albert, who lost his father during the attacks, read the names of about 3,000 people killed in New York on that day.
Stephen paused four times while reading the roll call to mark the times when the first plane hit the World Trade Centre, when the second plane hit, when the first tower collapsed to the ground and when the second tower collapsed.
The anniversary also saw the National September 11 Museum — which includes gut-wrenching artefacts, and graphic photos of the attacks opened to the public and tourists for the first time.
The memorial plaza was closed to the public for most of the day and only available to family members, then will reopen at 6 p.m. to the general public.