LOS ANGELES, Dec. 11 - Scores of extras loiter, their faces covered in soot. A man sprays gray insulation foam -- in lieu of concrete dust -- at what looks much like the corner of Church and Vesey Streets in Lower Manhattan. Another tosses reams of paper in the air. Nearby, others are debating precisely how to crush a fire truck and an ambulance.

And just over there, across a dirt road in this isolated industrial tract not far from Marina del Rey, the twisted facade and mangled girders of the wreckage of the World Trade Center are taking shape into a meticulously rendered mockup of ground zero.

A continent removed from the scrutiny of scarred New Yorkers, Oliver Stone's film about 9/11 rescue workers is deep into its second month of principal photography. And crew members working round the clock are dressing one of the most sensitive movie sets imaginable.

The film, which as of now is to be called, simply, "World Trade Center," tells the story of two Port Authority police officers, John McLoughlin and Will Jimeno, who were the last two rescue workers pulled from ground zero alive. It is billed as an uplifting story about everyday New Yorkers helping one another amid a cataclysmic tragedy. So for 20 days in October and November, the cast and crew were in the New York metropolitan area, filming at the police desk in the Port Authority bus terminal and along the route the officers took downtown on the morning of Sept. 11, 2001. They filmed scenes on the Staten Island ferry, the Long Island Rail Road and a subway train in Brooklyn. They shot in Clifton, N.J., near Mr. Jimeno's house, and in other suburbs.