NEW YORK (CBSNewYork) – A parking garage that was being demolished on West 57th Street between 11th and 12th avenues partially collapsed Wednesday, leaving one construction worker with minor injuries, officials said.

Workers digging inside the building around 2:30 p.m. when part of the structure came down, injuring one, according to officials.

“He actually was on the third floor, and when the floors pancaked down and collapsed, he rode the three stories down and walked out of the building. He was very lucky,” Fire Chief Dan Donoghue said.

All workers have been accounted for.

Debris could be seen lying on top of a parked school bus at the site.

Driver Dan Campbell said he was napping in the unoccupied bus when he woke up to see the building next to him crashing down on top of his bus. He climbed out the back door to safety.

“It is like a nightmare. I didn’t know what to do,” Campbell told CBS2’s Tracee Carrasco. “I wake up. I didn’t know where to turn.”

“All I see is smoke and the stuff coming down, and I look and stuff was still coming down … parts of the building.”

Debris atop a parked school bus following a partial collapse on West 57th street on Feb. 25, 2015. (credit: CBS2)

Debris atop a parked school bus following a partial collapse on West 57th street on Feb. 25, 2015. (credit: CBS2)

Construction workers at a project across the street stopped when they heard what they said sounded like a bomb.

“Like an explosion,” described Bill Jures. “It felt like an earthquake because the whole foundation, you felt it shake.”

“They must have been using a jackhammer or something,” added Rob Hartnett. “It was just like a loud banging sound.”

Residents in a nearby high-rise also heard the same terrifying sounds.

“I was sitting at my table having lunch, and I heard this really, really loud crash — this big boom,” said Thomas Falconer. “It freaked me out, so I went and looked out the window, and the corner of what was the West 57th Street garage — five stories had just collapsed onto the sidewalk.”

Aerial footage showed a cavernous hole in the center of the structure that was being demolished.

Emergency responders on the scene of a collapse on West 57th street on Feb. 25, 2015. (credit: CBS2)

Emergency responders on the scene of a collapse on West 57th street on Feb. 25, 2015. (credit: CBS2)

Netting surrounding the demolition site seems to have contained much of the debris, although a section of protective scaffolding near the site was crushed.

Emergency responders on the scene of a collapse on West 57th street on Feb. 25, 2015. (credit: CBS2)

Emergency responders on the scene of a collapse on West 57th street on Feb. 25, 2015. (credit: CBS2)

Crews were sifting through the debris Wednesday night, and 57th Street remained closed throughout the evening. The cause of the collapse is under investigation.

West 57th Street was closed in both directions between 11th and 12th avenues. Click here to check current traffic conditions.