An apparent chemical explosion rocked a 10-story building today, sending dozens of people to hospitals and seriously injuring a dozen, fire officials said.
In all, as many as 42 people were hurt in what appeared to be an accidental explosion, fire department officials said. Volatile chemicals stored in a basement of a sign company might have touched off the blast, officials said.
Mayor Michael Bloomberg tried to calm the fears of New Yorkers worried the explosion might be an act of terrorism.
"There is absolutely no reason at this point to believe there's anything suspicious about this explosion," he said.
Victims were taken to several hospitals with burns, severe head injuries and cuts. Twelve were critically injured, fire officials said. Police said three were likely to die.
About 100 firefighters rushed to the scene in the city's Chelsea neighborhood shortly before 11:30 a.m. They found a commercial building on West 19th Street with parts of the facade blown off, and windows blown out of buildings nearby.
New York City fire and police officials said the blast apparently erupted in the basement of an 80-year-old 10-story building that houses Kaltech Industries Group Inc., a sign-making firm.
Kaltech's general manager, Phil Morgan, told The Associated Press he felt two consecutive blasts in the company's ground-floor offices.
"One pushed me up from my chair, the second one had me out of my chair," he said. When it was over, the ceiling and a wall had come down. "Everything moved. The air was filled with dust."
Bill Franzen, a United Parcel Service driver, said he was injured when the facade of the building rained down on the sidewalk.
"I was walking down the sidewalk after making a delivery, heard a hiss and the whole wall came down on top of me," he said. "The only thing that saved me was I got pinned against a coffee wagon."
A worker on the damaged building's fourth floor described a difficult escape.
"The smoke was very thick," Mike Brassert told WINS radio. "I saw a gaping hole through the elevator shaft and into the building, and as much as I could tell it appeared that one of the floors was gone.
"We went down to the third floor, out a back window, jumped about 4 feet onto the building behind us and got down that way," he said.
Felt in Nearby Buildings
Daniel Motrano, a student at the nearby Apex Technical School, said that he was in class on the eighth floor when he and his classmates heard a loud boom and the floor shook.
"We all kind of sat there, stuck," he said.
After checking to see if the Empire State Building was still standing — a reflex after the Sept. 11 terror attacks, he said — Motrano and his classmates evacuated the building.
Apex officials said no students were injured in the partial collapse at the nearby building, though some of the windows in Apex's building were blown out.
Julie Ben Levi, who was working on the sixth floor of a brownstone building about a block away on 18th Street, said she felt her building shake from the explosion.
"We saw hundreds of people just running down the street, just gasping, on their cell phones trying to call," Levi said.
The collapse caused streets to be blocked off in the neighborhood of mixed commercial and residential buildings.
ABCNEWS' Michael McAuliff and Dierdre Michalopoulos and WABC-TV contributed to this report.