Associated Press photographer Richard Drew, who has worked for the agency for 51 years, has revealed he had no idea what he'd captured on 11 September 2001 until he returned to his office and reviewed the images on his laptop.
How he came to take the photo
Drew wasn't at the World Trade Center when American Airlines Flight 11 struck the North Tower at 8:46am. He was covering a maternity fashion show in Midtown Manhattan when his newsroom called to tell him a plane had hit the towers. He took the subway downtown and began photographing almost immediately upon reaching the southern tip of Manhattan.
Who the man in the photo may be
The identity of the man in the photograph, which became known as "Falling Man," has never been officially confirmed. Journalists have narrowed the possibilities to two men, Jonathan Eric Briley and Norberto Hernandez, whose names appear one apart on the parapets of the 9/11 Memorial.
How the photo was actually taken
Drew explained he didn't consciously compose the shot. As people fell from the building, he simply held his camera up and let it fire continuously. He said: "I have, I think, eight or nine frames of this gentleman falling, and the camera just happened to cycle in that time when he was completely vertical. I didn't see that picture really until I got back to the office."
The reaction to the image
The photo ran in newspapers the following day and drew strong reactions, with many readers finding it too distressing to look at. Elton John was a notable exception, later purchasing the photograph for his personal collection, describing it to The Guardian as "the most beautiful image of something so tragic" and calling it "probably one of the most perfect photographs ever taken."
A personal moment weeks later
Drew recalled a phone call from his daughter weeks after the attacks, while he was still photographing the aftermath, in which she told him she loved him. He said she still calls him every 11 September for the same reason, telling him it's "because I might not have survived."
Helping identify another victim
Drew also described helping identify a separate victim through his photographs, after a man contacted the AP believing he recognised clothing his missing fiancée had been wearing that day. Looking through the images together, the man confirmed it was her.
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