More than 3,000 people were killed when two hijacked airliners brought down New York's famous twin towers.

"Each tree would have a name on it, so any person who lost someone could go and see their name - it would breathe. It would be better than a bunch of names on a piece of marble."

Meyerowitz, 64, has shot thousands of pictures at the site over the past six months as the official photographer at the site dubbed Ground Zero.

The native New Yorker launched an exhibition of his photographs, supported by both the U.S. State Department and Museum of the City of New York, at the Museum of London this week.

"We live in a world of high rise buildings and we think of them as permanent. To see them exposed like that, to see the their innards - it was just like a human being, horrific and yet magnificent," Meyerowitz told Reuters.

The photographer reached the site four days after the attacks and recalls the impact of the mass of twisted metal.

"Everywhere you looked you could see razor blade edges. It makes you feel vulnerable and fleshy, then I realised what it must have been like to be dying inside this falling pile of steel."

Meyerowitz said he was moved to tears on occasions and praised rescue workers, who are still working around the clock searching for bodies and clearing up the debris.

This week British tabloid the Daily Mirror honoured firefighter Mike Kehoe, photographed climbing a stairwell as hundreds fled in the opposite direction before the tower collapsed, with a special "Pride of Britain" award.

Singling out one of his photographs of a memorial of flowers and soft toys amongst the rubble, Meyerowitz said: