UPDATED with production company statement. A year after a fire burned a Harlem brownstone used for production of the Edward Norton-directed Motherless Brooklyn, the New York City Fire Department has issued a detailed report that breaks down the cause of events. It points to some shocking lapses that contributed to the death of firefighter Michael Davidson.

While multiple lawsuits against the city and Norton’s production company are pending, the report serves as a cautionary tale worth absorbing by anyone who engages in location shoots for movies and TV shows.

Most shocking, per the report, is that Davidson and his fellow firefighters were unaware of the movie set alterations that converted the building’s interior into a set for the film that stars Alec Baldwin, Willem Dafoe, Bruce Willis and Norton. So while Davidson went downstairs to the cellar and sprayed water on the walls, he didn’t initially realize that this was a façade. When the enormity of the blaze became clear and the real fire burned through, the firefighter was separated from his team in the thick, toxic smoke and his oxygen tank emptied before he could escape.

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Norton and Willis on “Motherless Brooklyn” set Shutterstock

In addition, alterations to the movie set included placing highly combustible material on the walls throughout the first floor. Finally, the report flagged the fact that filmmakers and the Mayor’s Office of Media and Entertainment, which issues shooting permits, aren’t obligated to notify the fire department about planned shoots. All of these issues contributed to a tragedy that perhaps could have been averted.

On Thursday, FDNY issued its official report on the accident, which was covered by local media outlets including Newsday and the New York Daily News.

“The movie production placed highly combustible materials on the walls throughout the first floor,” the report said. “These movie walls created voids which initially concealed fire. The first units were unaware that these false walls were not intrinsic to the fire building.”

New York City Hall Paul Brown/Shutterstock

Davidson, 37, became disoriented and used up his entire oxygen tank, succumbing to smoke inhalation. Materials used for the set of the period piece, including Art Deco panels, ignited quickly and released thick, dark smoke.

The mayor’s office told Deadline in a statement that it “works on a daily basis with the FDNY to ensure safety on film sets.” The statement added, “We are coordinating with the FDNY to enhance our permitting questionnaire to ensure that the FDNY will have adequate information about proposed filming activity to determine if there are fire safety concerns.”

Edward Norton’s Class 5 Productions and the city have been named as defendants in a lawsuit by Eileen Davidson, the firefighter’s widow and mother of their four children. The suit is among three such complaints that allege the production disguised the true extent of the fire, with the city not having sufficient oversight. Earlier this month, a state court blocked an attempt by attorneys for Class 5 to have Davidson’s suit dismissed.

Attorneys for Davidson and for Class 5 did not immediately respond to Deadline’s request for comment on the FDNY report, but a spokesperson for the production company said the accident, while tragic, did not stem from anything the production company did. The boiler in the brownstone had 20 city code violations in 25 years, the rep added. “The actions by the building owner related to that boiler specifically, on and just prior to the night of the fire, are known to the FDNY investigators and will be commented on further in due course,” the production company said in a statement.”

As to the notion that firefighters were unaware the brownstone was being used as a set, the spokesperson said members of the FDNY were on the set days before the fire and presumably knew the score.

“This was a horrible tragedy and Lt. Davidson will forever be remembered by all of us as a true hero. But as the Report makes abundantly clear, the production team neither caused the fire nor took any action that caused Lt. Davidson’s death,” the statement added.

Michael Davidson Rex/Shutterstock

Davidson was mourned last March by thousands of firefighters and others in a funeral service at St. Patrick’s Cathedral and a procession through the city.

The cause of the fire is a matter of dispute. The FDNY originally determined that it was caused by a busted boiler that ignited nearby flammable objects, making the building’s owner responsible, not the film crew. But in a surprising twist, Fire Marshal Scott Specht – the lead investigator of the blaze – claims that the FDNY engaged in a “rigged investigation … to protect Ed Norton.”

In a notice of claim filed in December with the City of New York’s Law Department, Specht alleged that his superiors had “ignored the fact” that the film company “lied to [him] regarding the massive amounts of highly combustible, petroleum-based movie set materials that were overloaded into the building.”

He also said his superiors “ignored the evidence” that some of the wood screws that Norton’s film company installed into the hardwood floors were long enough to pierce metal-clad electrical cables and that after the blaze, some of those cables were “found to be pierced.” Read Specht’s full complaint here.

There are a range of safety protocols recommended by the Industry-Wide Labor Management Safety Committee for the Motion Picture and Television Industry, which is composed of guild, union and management representatives active in industry safety and health programs.

Its “General Code of Safe Practices” states, “All decorative set materials should be flame retardant or made of noncombustible materials if such materials will be exposed to hot lamps, fire effects or other ignition sources.” See all of the Contract Services Administration Trust Fund safety bulletins here.

Other fire-related safety recommendations include: “Obey all ‘No Smoking’ signs. Observe designated smoking areas and always extinguish cigarettes in the appropriate containers (butt cans).

“Fire equipment (hydrants, extinguishers, sprinklers, hoses, etc.) must be accessible at all times.

“Remember that lights placed too closely to props, sets and other materials may pose a fire risk and, therefore, make sure that lights are placed far enough away to alleviate risk.”

Greg Evans contributed to this report.