The FDNY says the fire broke out in the six-story apartment building on 67th Road in Forest Hills just before 5:30 a.m.
Raw video posted to the Citizen app showed angry flames leaping from the roof as firefighters responded to the blaze.
More than 100 firefighters responded to the scene of the two- alarm fire. The fire was under control just before 7 a.m., according to the FDNY.
No civilian injuries were reported but one firefighter was taken in serious condition to New York-Presbyterian Queens Hospital. The nature of that firefighter's injuries are unknown, according to the FDNY.
The Red Cross says it provided emergency housing and financial assistance to at least two families whose apartments were affected by the fire.
The cause of the fire is under investigation.