Oliver Stone's controversial film World Trade Center has had its world premiere in New York.
Police officer John McLoughlin (l) is portrayed by Nicolas Cage (r)
The film, starring Nicolas Cage, tells the true story of two police officers thought to have been the last survivors pulled from the rubble of the towers.
Officers John McLoughlin and William Jimeno attended the screening at the city's Ziegfeld Theatre.
Stone promised the film would show sensitivity after relatives of victims expressed concerns over its content.
"It's a great story. It's almost unbelievable," said the director.
He added that the people on whom the characters were based had been heavily involved in the production.
"We worked with them constantly," Stone said.
"Will and John were part of this. The rescuers were with us. The details are very exact."
The movie also stars Crash actor Michael Pena, and Maria Bello and Maggie Gyllenhaal as the wives of the officers trapped in the collapsed Twin Towers for 22 hours.
The men were in a group of five officers who entered the South Tower shortly before it collapsed. The other three were killed.
World Trade Center has received mixed reviews in the US.
The Hollywood Reporter said the story was told in a "sombre, focused and straightforward manner that serves the material extraordinarily well".
Variety praised Stone for "presenting this challenging, fact-based story with admirable restraint".
However it added: "World Trade Center yields lovely and touching moments but proves a slow-going, arduous movie experience."
Entertainment Weekly called it a "scrupulous and honourable film" but said there was a "fundamental lack of dramatic urgency".
"Stone, who at his greatest is the most harrowing of film-makers, now recedes into the conventionality of uplift," it said.