NEW YORK (CBSNewYork) — Firefighters have contained a two-alarm blaze that broke out at a building that’s under construction adjacent to the NYU Langone Medical Center in Manhattan.

PHOTOS: NYU Langone Medical Center Fire

Roofing insulation material caught fire at the building on 30th Street and First Avenue just after 12 p.m. Wednesday.

Video and images from the scene showed flames shooting from the roof, and thick, black smoke billowing from the building.

“We had a spectacular fire here behind me at a building under construction that will be part of NYU Medical Center,” FDNY Commissioner Daniel Nigro said.

No patients or offices were inside what will be the facility’s new Kimmel Pavilion, which is slated to open in 2018.

Construction workers immediately evacuated.

“You could smell it instantly just burning,” Kevin McCarron, who was on the sixth floor, said.

“Grabbed my bag and started heading down the stairwell. Some guys were blowing air horns telling everybody to get out,” Mike San Filippo, who also works on the sixth floor, said.

“We practice for days like this. Everybody got out unharmed, good mannered,” McCarron added.

The fire had little impact on the patients in nearby hospital buildings, officials said.

“A small amount of smoke was entering the hospital itself. The ventilation system was shut down promptly and that eliminated smoke from entering,” Nigro said.

Joe Lhota, the center’s chief of staff, said the normal operations continued at the hospital and there were no evacuations. Some patients were moved away from the windows.

The fire was confined to the construction site and was extinguished at approximately 12:45 p.m. During this time, hospital operations did not cease. As a precaution, some patients in rooms on the north side of Tisch Hospital facing the construction were moved to the south side of the floor. They have since been located back to their rooms. Currently we are investigating cause and the extent of damage,” a spokesperson for NYU Langone Medical Center said.

Lhota praised the FDNY and expressed his gratitude for the quick action.

“They were here faster than I ever thought possible, they put this fire out as quickly as possible and we very much appreciate it,” Lhota said.

“It was certainly concerning to me when I heard there was a second alarm on arrival at NYU Medical Center,” Nigro said. “We came here as fast as we could. The members by the time I got here had already extinguished the fire.”

No injuries were reported.

The FDNY tweeted late Wednesday that the cause of the blaze was an accidental spark from cutting metal.