The Naudet brothers were originally filming a rookie on the New York City Fire Department with the intention of making a film about the rookie's experience. Called out on a gas leak, one of the brothers goes to check it out when a plane flies by overhead; the cameraman turns to follow the plane and records the only known footage of the first plane hitting the towers. Later, he goes with the fire department into the lobby of Tower 1 as they begin trying to organize a rescue of the people still in the building, and is inside Tower 1 when Tower 2 collapses. The film gives various firemen's accounts of the events of the remainder of the day, from the initial crash to the building's collapse to the attempts to rescue survivors from the rubble.
CBS aired the film commercial-free on March 10, 2002, on the eve of the six month anniversary of 9/11. Hosted by Robert De Niro, CBS's airing was repeated on the one year anniversary as well; the DVD of the documentary was released in close proximity.