he Naudet brothers were originally filming Tony Benetatos, a probationary firefighter, on the New York City Fire Department assigned to Ladder 1 with the intention of making a film about the "probie"'s experience. On the morning of 11 September, Battalion 1 was called out on a gas leak, Jules rides with the Battalion Chief, Chief Joseph Pfeifer, to check it out. When a low flying plane flies by overhead Jules turns the camera to follow the plane and tapes one of only three known recordings of the first plane hitting the North Tower (Tower 1) of the World Trade Center (the others being a video shot by Pavel Hlava and a sequence of still frames taken by Wolfgang Staehle). The members of Battalion 1 that were investigating the gas leak were the first responders on the scene and Jules was allowed to follow the chief during the attempted rescue operation. Jules, Chief Pfeifer and several other FDNY Chiefs are inside the lobby of Tower 1 when Tower 2 is hit by the second aircraft and when Tower 2 eventually collapsed (Gédéon, meanwhile, is back at the firehouse, filming the reactions of probie Tony Benetatos and the rest of the firefighters as they try to deal with the disaster). 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.