New York City Mayor Zohran Mamdani’s administration has released more than 170,000 pages of records detailing the city’s response to the September 11 attacks and the air-quality conditions around Ground Zero.

The documents indicate that city officials were aware of serious contamination concerns, including asbestos and other toxic materials, while the public was repeatedly assured that the air was safe.

Mamdani said the records show that leaders failed New Yorkers by telling people it was safe to breathe the air, while advocates have accused previous administrations of withholding important information for decades.

The release follows years of legal pressure from 9/11 Health Watch and comes just before the 25th anniversary of the attacks, with the city also settling two lawsuits to make the records public, Fox News has reported.

The newly released records are expected to provide further insight into what officials knew about the health risks after 9/11 and could intensify criticism of how the city handled warnings about toxic conditions at Ground Zero.