Americans looked back on 9/11 on Tuesday with solemn ceremonies, volunteer service and a presidential tribute to "the moment when America fought back" on one of the hijacked planes used as weapons in the deadliest terror attack on US soil.
Thousands of 9/11 victims' relatives, survivors, rescuers and others who gathered on a misty Tuesday morning at the memorial plaza where the World Trade Center's twin towers once stood. President Donald Trump and Vice President Mike Pence headed to the two other places where hijacked planes crashed on September 11, 2001: a Pennsylvania field and the Pentagon.
Mr Trump and First Lady Melania joined an observance at the September 11 memorial in a field near Shanksville, where one of the jetliners fell to the ground after 40 passengers and crew members realised hijackers had taken control and tried to storm the cockpit.
Mr Trump said the fallen "took control of their destiny and changed the course of history".