Nearly 3,000 people died on US soil in the events of September 11 2001.
People across the United States have paused to remember the victims of 9/11 on the 20th anniversary of the terrorist outrage.
Joe Biden joined former presidents Barack Obama and Bill Clinton at a memorial event in New York City, 20 years to the day since the Twin Towers fell.
A mourner wipes tears from her eyes as she stands at the September 11 memorial (AP)
People tie ribbons to the fence at St Paul’s Chapel near the National September 11 Memorial and Museum (AP)
Former US president Barack Obama, Michelle Obama, President Joe Biden, first lady Jill Biden and former New York City mayor Michael Bloomberg attend the annual commemoration (Pool/AP)
Germano Riveira carries the flag of honour around the North Reflecting Pool during ceremonies (AP)
Melinda Moran and Haydee Lillo embrace after finding out they lost people who knew each other, next to the North Reflecting Pool (AP)
Bruce Springsteen performs during the commemoration (AP)
It was a day of sadness and reflection for people across the world (AP)
A bell is rung during a moment of silence (AP)
Former New York City mayor Rudy Giuliani, whose leadership was praised during the events of 9/11, was among those paying their respects (AP)
Following convention, current US president Joe Biden did not speak at the event in New York (AP)
Nearly 3,000 people died in the attacks, mainly in the World Trade Centre’s Twin Towers (AP)
The attacks ushered in a new era of fear, global conflict, increased powers for government and a changing sense of patriotic fervour, particularly in the US (AP)
Former president Bill Clinton – who was one of the first senior statesmen to arrive in New York after the attacks – and former US secretary of state Hillary Clinton (AP)
A US flag is placed on a name inscribed on the National September 11 Memorial – a day never to be forgotten (AP)
