Eleven people, including three firefighters, were injured after a five-alarm fire erupted in a Norwood apartment building Wednesday afternoon, according to the FDNY.

Firefighters responded to a 911 call at 12:26 p.m. for an explosion on the second and third floors of 374 E 209th St.

Video shows thick black smoke billowing out of the windows, with FDNY and emergency crews on scene.

Three residents are critically injured.

Three firefighters also sustained injuries. The severity of their injuries remains unclear at this time.

Fire crews are still working to extinguish the blaze.

No word yet on what caused the explosion.