The city of New York absolutely prohibited the recreation of 9/11 destruction or chaos on location. The filmmakers were not even allowed to film actors looking upward toward where the towers would be. The drive of the officers up to the site was permitted to be filmed, but all scenes depicting events at or near the WTC were filmed in Los Angeles.
Test audiences believed that Dave Karnes (Michael Shannon), the former Marine, was a Hollywood invention. This is, in fact, a true story that occurred. Karnes later re-enlisted in the Marine Corps and served two tours of duty in Iraq. Also, as reported by the Associated Press on August 14, 2006, the Marine identified only as Sergeant Thomas (who disappeared shortly after 9/11) has been identified as Jason Thomas, a former Marine who grabbed his uniform and immediately drove to Ground Zero to help. Because his identity was unknown at the time of filming, Sgt. Thomas - who is black - was portrayed by William Mapother, a white man. The producers have since apologized to Sgt. Thomas for the miscasting. Thomas has laughed it off and told them not to be concerned, stating, "I don't want to shed any negativity on what they were trying to show."
Three weeks before its August 9 nationwide release, producer Michael Shamberg and director Oliver Stone held private screenings of the finalized film for Port Authority officers and firefighters who risked their lives at the World Trade Center. The screenings were held in local multiplexes in the New Jersey/New York area.
In preparing for his portrayal of Sgt. John McLoughlin, Nicolas Cage focused on accurately speaking with a New York accent. And to also capture the fear and claustrophobia of McLoughlin's ordeal, Cage spent hours in a sensory-deprivation tank in Venice, California.
Oliver Stone used many of the East Coast www.PoliceActors.com members to play cops in the film. All members of PoliceActors.com are active or retired members of a law enforcement agency who are also Screen Actors Guild members.
Officer Scott Strauss, a first responder with the New York City Emergency Services unit, was offered the chance to play himself in the film. However, Strauss refused to do so and Stephen Dorff was then cast to portray him. Strauss's services as a consultant were retained for the film to which he didn't accept payment.
Due to her infamous quote that "America is responsible in some way" for the 9/11 attacks, Maggie Gyllenhaal personally offered to withdraw from the project to Officer William Jimeno and his wife Allison Jimeno. They both declined and gave their blessing for Gyllenhaal to take the role.
Before acting Steve Buscemi was a fire fighter in New York City. When his acting career took off he left the fire department he was working for. When 9/11 occurred Steve flew to New York and helped his old fire department with rubble at Ground Zero.
A billboard for Zoolander (2001) is visible in one shot, as the shadow of a hijacked airliner descends over New York City. That film, released shortly after the 9/11 attacks, had images of the World Trade Center digitally removed.
Was one of two 9/11 inspired films to be released in the same year, the other being United 93 (2006), based on the flight of the same name which crashed into a Pennsylvania field after the passengers thwarted the terrorists' plans to crash into the White House.
Oliver Stone thought of casting Kevin Costner as Sgt. John McLoughlin, his JFK (1991) lead. Costner had narrated the 2006 documentary On Native Soil (2006), about the 9/11 Commission Report's investigation of the causes of the terrorist attacks and what could have been done to prevent them from happening. Paramount Pictures was concerned that Stone and Costner would then delve into another conspiracy theory.
One of the victims of the WTC attacks was David Angell. He worked on the TV series "Cheers", "Frasier" and "Wings" for the television division of Paramount Pictures, the studio behind "World Trade Center".
The plane that first hit the World Trade Center was American Airlines Flight 11, and UAF 175 struck the South Tower 17 minutes later at 9:03am, September 11th, 2001. The other planes crashed into the Pentagon in Washington DC and the other in rural Pennsylvania.
Viola Davis appears in the film as the mother of the elevator operator at one of the Towers, talking to Maria Bello in the hospital. Viola also appeared in Extremely Loud & Incredibly Close (2011), which was another film involving 9/11, playing Abby Black, the first person that Tom Hanks' son meets on his journey to find what that key fits.
In the movie the satellite photo of the east coast from space shows clear day over New York which is correct on Sept 11th but a large hurricane just off the coast of Long Island New York is not shown in the photo used in movie.
Maggie Gyllenhaal plays the wife of a World Trade Center victim. Her brother Jake Gyllenhaal was the audio-book narrator for "The Man Who Walked Between the Towers", a book based on high wire artist Philippe Petit's walk between the towers in 1974.
Nicholas Cage, Michael Peña, Maggie Gyllenhaal, Jon Bernthal, Jay Hernandez, Viola Davis, and Michael Shannon have all appeared in Superhero adaptations. Cage was the title character in Ghost Rider (2007) and Ghost Rider: Spirit of Vengeance (2011), Gyllenhaal was Rachel Dawes in The Dark Knight (2008). Peña and Bernthal are both in the Marvel Cinematic Universe with the former appearing in Ant-Man (2015) and the latter appearing in Daredevil (2015) and as the title character in The Punisher (2017). Hernandez, Davis and Shannon are in the DC Extended Universe with the former two in Suicide Squad (2016) and the latter in Man of Steel (2013) and Batman v Superman: Dawn of Justice (2016).
Although not emphasized in the film, McLoughlin and Jimeno were in extremely precarious health after their rescue and slipped into critical states multiple times during their stay in the hospital. Both men had to retire from the Port Authority on disability. They were still undergoing surgery for their injuries at the time the film was released.
Jeanette Pezzulo, the widow of Officer Dominick Pezzulo, demanded that her husband's death be edited in the final version of the film. Jay Hernandez portrays the late Dominick Pezzulo, who died in the collapse of the World Trade Center towers. Unfortunately the abrupt cut to Pezzulo dead after he fires his signal shot made some viewers think his death was a suicide.
John McLoughlin mentions a Ben & Jerry's ice cream shop while navigating the mall concourse; Ben & Jerry's was a tenant of the World Trade Center Mall at the time of the attack. The real shop was small kiosk located near the entrance of 2 World Trade Center and was destroyed in the collapse. The employees working that day survived.