Health risks from asbestos and other toxic materials were questioned Sunday following the blaze that killed two firefighters in an abandoned skyscraper being dismantled next to the World Trade Center.
Results from air-quality tests around the building in lower Manhattan were expected later in the day, authorities said.
The blaze broke out Saturday on the 17th floor of the former Deutsche Bank office building, a floor that had not yet been cleaned of toxic debris spread by the Sept. 11, 2001, terror attacks, Environmental Protection Agency spokesman Bonnie Bellow said.
The once 40-story building was abandoned after the attacks because of extensive damage from wreckage falling from the towers and contamination by toxic dust containing asbestos, dioxins, lead and other materials. It had been largely gutted by demolition crews and workers have been taking apart its steel skeleton one piece at a time.
The cause of the fire was unknown, but Mayor Michael Bloomberg said it might have been fueled by plywood, boxes and other flammable supplies related to the dismantling work.
A worker in the building discovered the fire on the 17th floor, Fire Commissioner Nicholas Scoppetta said.
More than five dozen fire vehicles, carrying more than 270 firefighters, were sent to the site as pieces of burning debris fell to the streets. Smoke was visible from midtown Manhattan and the New Jersey side of the Hudson River.
Nearby buildings were evacuated, and residents waited for hours before they were allowed to return.
"We heard this crackling," said Elizabeth Hughes, who saw the fire from her rooftop deck across from the Deutsche Bank tower. "And then a huge fire that went up three floors fast. It was massive."
Firefighters had to use ropes to haul hoses up from the street to douse the blaze in the partially dismantled tower, Scoppetta said.
The building's structure was secure and in no danger of falling, Bloomberg said.
The firefighters who died, Robert Beddia, 53, and Joseph Graffagnino, 33, were trapped and inhaled a great deal of smoke, Mayor Michael Bloomberg said.
The collapse of the twin Trade Center towers across the street killed 343 firefighters. Eleven of them came from the same firehouse where Beddia and Graffagnino were based.