Twenty-five years after 9/11, New York Mayor Zohran Mamdani announced Tuesday the release of tens of thousands of documents which, according to him, revealed cover-ups by the city regarding air toxicity after the attacks.
“ These documents show what the city knew about the presence of toxic air around “Ground Zero“, when it became aware of it, and how it acted to limit its legal liability.«", the mayor said at a press conference.
This online publication was decided upon following a legal agreement with the 9/11 Health Watch association, a victims' advocacy organization that had taken legal action to force the city to release the information it possessed.
Months of pollution and residual dust
In addition to the 2,977 people who died in the United States on the day of the September 11 attacks, mainly in New York, more than 9,400 others have died from illnesses related to their exposure to the attacks, according to the federal program set up to ensure their medical follow-up.
Dust clouds swirl over southern Manhattan moments after the collapse of one of the World Trade Center towers on September 11, 2001 in New York (Credit: Getty Images North America / AFP/Archives- Spencer Platt)
After the initial dust cloud following the collapse of the World Trade Center towers, months of pollution and residual dust ensued, leading to cancers that still affect thousands of New Yorkers today.
“ People became ill because the leaders they trusted lied to them, telling them they could safely breathe toxic air.«insisted Zohran Mamdani.
These documents, which will be released online in waves over 12 months, could implicate two of his predecessors: Rudy Giuliani, in office at the time of the attacks, and then Michael Bloomberg, from the winter of 2002.
«"The city knew"»
Some of the 173,000 documents published on Tuesday relate to "« discussions that the Giuliani administration was having at the time regarding its legal responsibility and health risks«", New York City Chief Counsel Steven Banks stated during the press conference.
Former New York mayor Michael Bloomberg, June 23, 2026 in London (Credit: AFP/Archives – Justin Tallis)
Another document highlights "« information provided by Congressman Jerry Nadler »"under Michael Bloomberg's leadership"« regarding the concerns of residents of southern Manhattan »"as for the quality of the air they were breathing.
When contacted by AFP, the entourages of the two former mayors did not immediately react.
Read alsoThree-quarters of the firefighters who responded on 9/11 developed health problems
When questioned about the names of the political figures who had concealed information from the public, Zohran Mamdani dodged the question, stating only that "« This concerns a large number of people whom New Yorkers have trusted.“.
“ What we all knew, those of us who lived in Lower Manhattan, was that there were toxic substances in the air and on the ground, on the windowsills and in the air conditioners (…) and that they remained there for months«" , said comedian Jon Stewart, a leading figure in the defense of 9/11 victims.
“ Everyone knew it, and it now appears clear that the city knew it too.«" he continued.
Former New York mayor Rudy Giuliani attends the 9/11 commemorations on September 11, 2025 in New York (Credit: AFP/Archives – Timothy A.Clary)
Ben Chevat, director of the 9/11 Health Watch association, thanked Zohran Mamdani for being "« the first mayor in 25 years to finally begin to answer the question: What did the city know about the dangers linked to the toxic cloud at Ground Zero, and when did it become aware of them?.
On September 11, 2001, two hijacked planes crashed into the two towers of the World Trade Center, a third ripped through the Pentagon, and a fourth, which appeared to be targeting the Capitol or the White House, crashed in a wooded area of Shanksville, Pennsylvania, after a counterattack by the passengers.
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