A series of emails sent and received from within the White House on September 11, 2001, have revealed the shock of US leaders as they reacted to the terrorist attacks.
Aides to then-President George W Bush sent the series of emails, as family members and friends expressed their horror at the attacks in New York, Virginia and Pennsylvania.
Images taken of Mr Bush and his senior advisers in the secure bunker underneath the White House, released by the National Archive, also show them battling to come to terms with the attacks.
Among the emails were:
8:56am - "Turn on CNN" - Tucker Eskew, director of the White House media affairs office, emails three colleagues
9:20am - "Today is Pearl Harbor" - David Horowitz emailed this to Mary Matalin, an adviser to Vice President Dick Cheney.
9:51am - "Precedent for Co-ordinated National Emergency Response" - White House lawyer Jay Lefkowitz emails deputy chief of staff Joshua Bolten.
5:07pm - "Unbelievable. Just got back into the White House, after having been in the 'bunker' all afternoon." Clay Johnson, a longtime friend of the president replies to his sister Ellen.
7:59pm - "Soon enough, the day that no one in the White House had ever imagined comes to an end. But the nightmares were not over." Deputy White House staff secretary Stuart Bowen replies to an email from presidential adviser Karen Hughes.
The emails were released by the George W Bush Presidential Library to The New York Times after an open-records request.
Mr Bush was on a visit to Booker Elementary School in Sarasota, Florida, when he was given the news of the attacks.
The newspaper has said the emails are incomplete, with the vast majority of messages sent on 11 September, 2001 remaining withheld for national security reasons.
The release comes on the fourteenth anniversary of the terrorist attack.
President Barack Obama and First Lady Michelle observed a moment of silence at 8.46am - the time the first plane crashed into the North Tower of the World Trade Center.
Bells also tolled across New York as families of the victims read out their names at ground zero.
Some 2,977 people were killed when hijacked aircraft were flown into both towers of the World Trade Center and into the Pentagon, and a fourth plane crashed into the ground near Shanksville, Pennsylvania, after passengers attempted to subdue the attackers.
