THE sobbing at the back of the auditorium was not the sentimental sniffling you normally hear at the cinema. It was the full-throated grief more typically heard in a hospital or a funeral home.

On Tuesday night anguished families wailed as they watched the last moments of their loved ones’ lives unfold on screen at the world premiere of United 93, by the British writer-director Paul Greengrass, the first Hollywood film about the September 11, 2001, hijackings.

About 90 relatives of the 40 victims mustered the courage to walk the red carpet to watch Mr Greengrass’s disturbingly realistic depiction of the passenger revolt that brought the aircraft down in a field in Pennsylvania and probably saved the Capitol building from attack.

“It’s horrific to see my brother, Edward, on the screen, knowing what is going to happen,” Gordon Felt said. “It’s shattering, but it needs to be. This is a violent story.”

Some cinemas in New York have withdrawn the graphic trailer for United 93 in the run-up to the scheduled release on Friday because of protests from traumatised residents that it was “too soon”. But Robert De Niro’s Tribeca Film Festival — founded to revive the Lower Manhattan neighbourhood after the 2001 attacks on the World Trade Centre — insisted on holding the premiere of Greengrass’s film.

“Some people will not want to see the film,” Greengrass said. “People find the subject too hard. I respect that. Remembering is painful. It’s difficult. But it can be inspiring and it can bring wisdom.”

Despite the ornate surroundings of the Ziegfeld Theatre in Manhattan, the event was almost certainly the most sombre film premiere in the history of New York. The audience gave the victims’ families a standing ovation before the screening but were overwhelmed towards the end by the open weeping of the relatives and left the auditorium in stunned silence.

The audience included former senator Bob Kerrey, a member of the 9/11 inquiry; Ray Kelly, the New York City Police Commissioner; the actor Steve Buscemi, a former firefighter who joined the rescue effort at Ground Zero; and the air-traffic controllers who portrayed themselves in the movie. But the British-based Iraqi actor Lewis Alsamari, who played one of the hijackers, was unable to attend because he could not obtain a US visa.

The film, made with the co-operation of the victims’ families, adheres scrupulously to the plot laid out in the 9/11 report commissioned by Congress, and it portrays the hijacking in real time. The result is a kaleidoscope of shards of information about the attack — including real footage of the blazing World Trade Centre towers — without any attempt at embellishing the story. It starts with the hijackers reciting the Koran in their hotel room and ends abruptly.

“It’s a powerful story. It’s hard to watch. But it’s an important motion picture,” Alice Hoagland, whose rugby-playing son, Mark Bingham, took part in the revolt, said. “As a mum who lost a son fighting terrorism on Flight 93 and as a flight attendant, I know we have a lot to do. Although it ended up in tragedy, there is a glimmer of hope because you see the building of Congress still standing.

” Ben Sliney, a Federal Aviation Authority official, who portrayed himself in the film, said: “The stars are truly those people in the plane.That is something I would have done. I think I would have gone down fighting like that. It’s the American way.”

Ken Nacke, whose brother was one of the passengers, found himself “rooting for them, for a different outcome”. Omar Berdouni, a Moroccan actor who played one of the hijackers, rejected suggestions that Arabs might see the film as a tribute to the terrorists. “To an Arabic audience, the people do not represent Arabs or Muslims,” he said. “These people are from a sect. They do not represent me or my society.”

Greengrass said that it was humbling to take the film to New York. “There is a great debate going on on where we are going in the post-9/11 world,” he said. “This is part of the process of film-makers saying, ‘We would like to join that conversation’.” The writer-director, whose features include Bloody Sunday, said that he was chastened by his experience of working in Northern Ireland.

“Northern Ireland is one of the few examples of where political violence has been negotiated away, thanks to the political engagement of all the parties in a peace agreement,” he said. “My time making films there has shown me it takes a long time.”

WHAT THE CRITICS THOUGHT

It’s a long, brutal and honest look at a shattering event some Americans would apparently prefer not to see depicted — but also a respectful, inspiring one that’s in no way exploitative or emotionally manipulative

Lou Lemenick,
New York Post

United 93 is built of shattering images. This is first-rate film-making: taut, watchful, free of histrionics, as observant of the fear in the young terrorists’ eyes as the hysteria in the passenger cabin, and smart enough to know this material doesn’t need to be sensationalised

David Ansen,
Newsweek

Filmed in real time and shot with handheld cameras, it has the urgency and grit of a documentary rather than a big-studio movie. We will never know exactly what transpired aboard that flight, but United 93 gives us an educated guess

Claudia Puig,
USA Today

The movie is as much journalism as art: It’s about how things work — and, on this day, how things don’t work

David Edelstein,
New York magazine

Many films whip up tension with cunning and manipulation. This movie plays it straight. A few people made extraordinary use of those tormented minutes, and United 93 fully honours what was original and spontaneous and brave in their refusal to go quietly

David Denby,
New Yorker

Click here for an interview with the director of United 93