Five years on from the September 11 attacks, film-maker Oliver Stone has produced the first Hollywood account of what happened at the World Trade Center. Keiron Pim heard him and survivor Will Jimeno explain why they made it.

Only 20 people were pulled alive from the wreckage of the World Trade Center in the aftermath of the September 11 terror attacks, so when one of them walked into a room in the Dorchester Hotel this monthit was no surprise that the assembled group of journalists broke into a warm and spontaneous round of applause.

Will Jimeno lay trapped in the ruins of the North Tower for almost 12 hours before being extricated from the rubble and rushed to hospital, where he spent nearly three months. The story of how he and fellow Port Authority policeman John McLoughlin were rescued forms the basis of Oliver Stone's new film, World Trade Center, which Jimeno and Stone were promoting in London.

To see the ebullient Colombian-born Jimeno in the flesh brought home the reality of the tragedy for those of us who watched it on television but had no direct involvement. At a risk of sounding trite, his story also shows that a few heart-warming moments emerged amid the unimaginable horror.

It was only when Jimeno left the platform on which he and Stone had been seated for the press conference that he showed a sense of any vulnerability. He needed two men to help lower him from the dais because he could not bend his shattered leg.

“It took three hours to extricate me, and another seven hours to extricate John,” he said. “I have a brace and my leg is disfigured. I have physical injuries, and with the love and support of people I have been able to get through that. There was also the post-traumatic stress disorder. Through therapy I've managed to live through that.”

Being closely involved in the production of the film must have proved traumatic at times but Jimeno emphasised the importance of honouring the dead, a concern he shares with the Vietnam veteran director.

“Oliver is a combatant of war, he knows what it is to lose a comrade. People who have seen combat know there's a certain obligation to honour those who have lost their lives.

“After I saw it for the first time I walked out and gave him a hug and a kiss. I hope people stop sharpening their knives for him and do it for someone else, because he is doing a lot of good for the world.”

Stone himself has suggested recently that whereas in the past his films focused on exploring the world's shadowy corners, he sees this film as bringing light to where there is darkness.

At the Venice Film Festival this month, he said: “In the past I made very intense films, very powerful films about dark subjects. I did Vietnam at a time when America was very prosperous and there was no war. Now is a time to go the other way - that's my nature - and I want to be positive.

“This is a story which moves the heart. The heart unites, politics divides. It's important that we light a candle in the darkness.”

Its uplifting message has brought World Trade Center largely positive reviews in America, although the film has met a cooler reception on this side of the Atlantic. To British eyes, at least, its weakness lies in its sentimentality. Stone's portrayal of the terrorist attacks spares no time cutting to the action; as soon as the scene is set - Manhattan, a warm autumnal morning, New Yorkers starting their day and wise-cracking police crews bustling into their station - we see a vast shadow of an aeroplane speed low across a skyscraper and then watch the cops' faces as they hear an almighty thud. Thankfully Stone refrains from showing the planes hitting the twin towers: an effective, and sadly rare, moment of understatement in an often heavy-handed movie.

McLoughlin and Jimeno were New York Port Authority policemen, just two among the many brave servicemen to enter the WTC when everyone else was trying to escape it. Because the disaster happens so early in the film we cannot feel too much for them as individuals, as there has been so little time for character to be established. Instead, and to be fair to Stone this may have been his intention, they emerge as Everyman figures, to whom we can all relate even if we do not feel that we know them. As Jimeno pointed out: “No matter what religion, race, creed or colour you are, we all bleed the same and feel the same.”

Nicolas Cage plays McLoughlin, the gruff older cop who now wishes he'd been closer to his wife and kids, and Michael Pena is Jimeno, the sparky younger guy whose wife Allison (a very convincing Maggie Gyllenhaal) is pregnant with their second daughter.

The film cuts regularly to their worried families at home, and further emotional context comes from a series of sickly soft-focus flashbacks. One such scene, in which Allison McLoughlin lovingly makes the bed with slo-mo billowing white sheets, resembles nothing so much as a washing powder advert. Perhaps this is where American and British sensibilities differ; this scene prompted a bristle of derision at the press screening at UIP's headquarters in Golden Square; equally you could imagine it playing well in the American heartlands.

“We were looking for these familiar, almost banal moments in a relationship,” Stone explained. “Those little things you do, whether it's smelling the sheets or his blue jeans, little moments you take for granted.

“It has been noted in my work in the past that I have been interested in death, and it was interesting to work with two people who have been as close to death as anyone gets in their lives. I think they survived because of metaphysical reasons as well as physical reasons. They had family and beliefs and life and faith. The mind kept them alive.

“I think the feelings of the 20 survivors are covered somewhat by the feelings of those two and their wives. The beauty of this was that it was apolitical, it was a microcosmic story.”

This is not to say that the irrepressible Stone does not feel strongly about the political situation sparked by September 11.

“I really feel that if the president had a little more sense of history, had been a little more mature, there would have been a more moderated response and we wouldn't have lost our heads as a nation.”

Stone added that “Dave Karnes didn't want to co-operate [with making the film] because of my anti-Bush feelings”, referring to the real-life ex-Marine who, on the morning of September 11, walked out of his job as an accountant, dug out his old uniform, had a buzz-cut at the barbers and made for Ground Zero, searching for living people until he found McLoughlin and Jimeno. Of the 20 survivors, they were the 18th and 19th to be rescued.

“This film is a memorial; its function is to remember. Believe it or not, in America many people are forgetting about 9/11.”

Presenting a film in this way, as existing solely to preserve the truth, is of course an open invitation for critics to pick holes in it. And sure enough people have been quick to point out the inaccuracies: for instance, the constraints of a two-hour film format mean that the rescuers' heroism is underplayed, as a painstaking 10-hour process is, understandably, trimmed to a manageable 20 minutes or so. Unfortunately the film also uses a white actor to play Jason Thomas, who joined Karnes in the rescue, when in real-life he is black, a mistake for which the production team has apologised.

What World Trade Center does best is evoke atmosphere. Lying stricken under rubble in the smouldering foundations of the WTC, faces caked in ash and grit, McLoughlin and Jimeno fade in and out of consciousness and reminisce about their loved ones when they are able to overcome the agony and draw the sufficient breath to speak.

There are chilling moments in the claustrophobic scenes beneath the collapsed tower, and you cannot help but flinch as the two characters lie unable to avoid a hail of falling masonry, prone like Prometheus: the movie does have an epic, mythic quality in its portrayal of human endurance. Their colleagues lie dead nearby, handguns firing bullets randomly in the heat. Then the flames begin to flicker from below… it is a hellish vision, skilfully conjured. It was not surprising to learn that the filming process was riddled with difficulties.

“Building the sets was extremely complicated. We had to make the sets seamless with the clips and the computer imagery we used,” said Stone. “I developed an allergy that affected my lungs. I sucked in a lot of smoke, toxic rubble and debris.

“The producers also spent hours and hours with widows' groups, political groups.”

On top of coping with his physical ailments and working delicately with bereaved families, he had to balance the practicalities of movie-making with ensuring the scenes in the rubble of the WTC were as realistic as possible.

“I drove Oliver crazy,” said Jimeno. “I said: 'It's not cramped enough, it's not dark enough', but how else do you fit a camera crew in there?”

When Jimeno heard the idea of Hollywood producing a film of his story he had reservations. “I will be honest with everybody, we were hesitant. I said: 'How does Hollywood take our story and put it on the big screen?'

“But they said Oliver Stone was going to be director and I was floored. Whether you love or hate this man, and I love him, he is not going to let political correctness affect what he is going to do.”

A decorated war veteran, Stone is known for his uncompromising filmmaking. As well as three films set in Vietnam - Platoon, Born on the Fourth of July and Heaven and Earth - he directed a Richard Nixon biopic and the controversial JFK, which postulated that the John F Kennedy assassination was planned by government insiders rather a lone gunman.

He's also renowned for using a mixture of film techniques - different types of film stock, garish hallucinatory sequences, quick cuts between scenes - but is relatively restrained and sober in World Trade Center, aside from the soft-focus flashbacks and a scene where a parched Jimeno slips out of consciousness and has a vision of Jesus bearing a water bottle. Given the inherent emotion of the story, the film's attempts to lay more sentiment on with a trowel often seem mawkish and redundant. It's hard not to conclude that World Trade Center moves us most effectively when it is least trying to do so. But despite the violent subject, it marks a newfound calmness to Stone's film-making, which the former hell-raiser ascribes in part to his advancing years.

“I'm very proud of turning 60. I think the Asians are right, I think the older you get the better you get. I think age should be taken more seriously, there's too much emphasis in this world on beauty and youth,” he said.

“I'm really enjoying the overview. I feel like I know much more. If I had my time again I would avoid some of the excesses of my youth! But I wouldn't abandon them entirely.”

t World Trade Center, certificate 12A, is at cinemas now.