It took 25 fire trucks and 105 firefighters to extinguish the inferno, which started shortly before 5 a.m. at 69-46 Sybilla St., near 70th Avenue, the FDNY said.
“It was huge,” said Frank Gulluscio, district manager at Community Board 6, of the fire.
The flames were brought under control just before 7:40 a.m., according to the FDNY.
"There were no injuries at this vacant, ancillary building," a spokesman for the DOT said in an email, adding that "there will be no long-term impacts on the agency’s operations."
It was not immediately clear what caused the blaze in the one-story brick building.