Restaurant fires seem to be a common occurrence in NYC these days, as a fire that started in the duct work of a restaurant quickly evolved into a gigantic three-alarm blaze.

Fire officials say more than 140 firefighters appeared on the scene to aid in extinguishing efforts. The blaze intersected the TSQ Brasserie at Seventh Avenue and West 49th Street and eventually spread to other areas of the 12-story building.

“It was a pretty complex situation,” said FDNY Deputy Chief John Hodgens. “The fire was in between three buildings, and we had to have personnel in all three buildings identifying exactly what was burning.”

Since the fire started in the duct work, firefighters had a particularly tough time extinguishing the blaze. With rectangular duct, extra space – up to three inches extra – must be factored in for the connections and reinforcements needed at each joint. This is not a consideration when installing spiral ductwork. Hodgens explained the procedure for putting out the blaze.

“You have to get water into that duct, and the easiest way to do that is from the roof,” he said. “So, we had to stretch hose lines to the roof, open up the duct work, get water in there, also work on the duct work from the ground floor up.”

Firefighters did manage to get the fire under control, but not until almost three hours after it began. According to FDNY officials, the fire broke out around 4:50 a.m. and was still going up until about 7:40 later that morning.

Fires of this caliber generally cause a lot of injuries, but in this case, only three people were injured. One civilian was treated at Lenox Hill Hospital, while two firefighters received medical care at the scene of the fire.

While the fire started in the duct work of the 12-story building, fire marshals are still in the process of determining what started the blaze.