New York Fireman Richard Picciotto was inside the Twin Towers evacuating office workers when the second tower collapsed. STEVE PRATT recounts his amazing story.

When Richard Picciotto opened his eyes, he thought he was dead. He was surrounded by darkness. "For a few seconds, I imagined that maybe your thought process goes on after you've died," he says.

Slowly, the black cloud of dust and debris cleared enough for the New York firefighter to realise he was alive - and trapped in the rubble of the Twin Towers.

He had survived the terrorist attack on September 11 when the world, literally, fell down around him. He was inside, evacuating office workers with other firemen, when the second tower collapsed.

A dozen or so survivors were trapped in a stairwell that had become a cave-like space beneath the rubble and which he feared could become their tomb.

It's difficult to conceive that anyone survived as 51-year-old Picciotto - Pitch, to his colleagues - produces a photograph of the scene, pointing to something jutting out of the desert of flattened metal and rubble that's just about recognisable as a stairwell.

A fireman for 29 years, he has yet to come to terms with why he survived when so many of his colleagues didn't. "People who are spiritual say, 'God has a reason why you are still alive'. I say, I wish I knew why that was," he says, talking in York during a tour to promote his book about the ordeal.

He reckons he was one of the last people in the civilised world to see the towers come down. He'd only heard the collapse and seen the aftermath before watching the event on TV on his return home

'I was inside but didn't see it happen," he says. "When I watched the first tower come down on TV, I knew I was on the 35th floor of the other. And I definitely knew where I was when the second tower came down - I was in it. I don't believe it, but that's where I was."

Trying to piece together his ordeal within the framework of September 11 events led to writing Last Man Down: The Fireman's Story. He wanted to chronicle the day in New York City fire service history when 343 of its members were lost. Originally, his jottings were intended for firemen only.

"Mine is one of the good stories from that day," he says. "My story started circulating about how I survived and friends wanted me to tell them the story. I couldn't refuse anyone and it's a long story to tell properly. Firemen were encouraging me to write so more people could read it.

"It was cathartic for me. I told the story hundreds of times and, for me, that helped. Other people don't want to talk about it. I know some firemen who won't go to the site. Whatever they have to do to get through is fine by me.

"When I was home recovering I couldn't get away from it on TV. I was watching everything for a long time. Finally I said I must stop. I was just watching and going to funerals. It was such an emotional rollercoaster for me and a lot of firemen."

He could never have imagined what would follow as he set out for the World Trade Centre, shortly after the first tower was hit and with only sketchy reports of what was happening.

He was on the 35th floor of the north tower when a sound - "like being at a station and a train coming towards you" - stopped him in his tracks. It took a few moments before realising the other tower had collapsed.

As a battalion commander, Picciotto was the highest-ranking fire department officer there and he ordered the evacuation of the building. When those fleeing found two stairwells blocked with rubble, he directed them to a third stairwell. He knew the layout through the clear-up of the 1993 World Trade Centre bombing.

He checked each floor as they made their descent. On the twelfth floor, they came across 50 people, mostly elderly and disabled, in an office, waiting for help. Firefighters formed a human chain to help them down the stairs.

"We got down into the single number floors and I started to think, 'we're going to get out of here'," he recalls. "Then the noise started again. I thought that was it. I thought, without a doubt, that I was going to be dead within a matter of seconds."

Then he fell into space as the floor disappeared from under him. He woke, covered in inches of black dust and rubble, and thought he was dead. He was cut and bruised but alive, after falling what he reckons was three floors.

He made contact with the others on different levels in the stairwell remains. Eventually, they saw light and made radio contact with the outside world.

Eventually, Picciotto climbed out and began walking across the tower's remains to direct rescuers towards the trapped survivors, sounding his megephone to attract attention. Several hours later help finally reached the survivors.

Picciotto is back with the fire service, on light duties. He expects to retire next year, although obviously reluctant to leave the fire service. "I love what I do, but life goes on and I realise how precious life is. I want to enjoy it," he says.

"But it's a tough break to make because it's more than a job, it's a vocation. You don't ever stop having that mentality."

He's been back to Ground Zero to watch excavations, where workers are still clearing the site. The bodies of many of the firemen who died have not been recovered. "We're still digging. There'll be no closure until the site is completely clear," he says. "I will never forget it. Nor do I want to forget it. Time heals, they say, and I hope it does."

*l A royalty from Last Man Down (Orion, £16.99) will go to a foundation to assist firefighters and their families affected by events of September 11.