NEW YORK (CBSNewYork) — Monday’s frigid conditions made it tough for firefighters in Queens.

Investigators said one person was seriously injured and three firefighters were hurt trying to put out a fire at a medical supply company in College Point, CBS2’s Natalie Duddridge reported.

Thick, dark smoke engulfed a commercial building on 14th Avenue in College Point. The fire broke out at 7:30 a.m. Workers next door said they smelled it and heard a loud noise.

“I saw the building was smoking white then you saw black smoke, which means everything inside of the building started to smoke and started to burn,” Cesar Catala said. “We came inside 10 minutes later. You started to hear pop, like a loud bangs means something was exploding inside.”

Watch: FDNY Presser On College Point Fire 

That noise turned out to be exploding oxygen tanks that were stored inside B&B Systems, a wholesale medical supply and toy company. The FDNY said the fire started in the basement and moved to the first floor of the building, but did not spread to surrounding structures.

A man who worked there was rushed to Jacobi Hospital in critical but stable condition.

“That civilian was rescued by members of Rescue Co. 4. He was found in the rear of the building,” Assistant Chief Tom Richardson said.

Dozens of firefighters worked for hours to put out the three-alarm fire, rotating shifts every 20 minutes to keep warm.

Three firefighters suffered smoke inhalation. The bitter cold proved to be especially challenging.

“Slipping, hazards, getting hose lines in position. We were able to overcome those situations so far,” Richardson said.

What made things worse was the burning plastic and the smell it threw off.

“The stench was really bad with the wind and the cold for the fire. I feel sorry for the firemen,” Catala said. “Firefighters have a hard job and I’m sorry for the person who got hurt.”

The FDNY said it was going to take several more hours to full control the situation. The Department of Buildings was then expected to assess if the building and others around it were safe enough to investigate.