A Crown Heights building burst into flames just before noon on Monday, injuring five people, according to the FDNY.

The fire broke out on the second floor of the Union Street apartment building. Neighbors say that before firefighters arrived at the scene, bystanders ran into the building to rescue two elderly women who live on that floor. 

"One of the women was banging on the window and the smoke was pouring out," said Noel, one of those bystanders who acted quickly to help his fellow Brooklyn residents. "Some folks were already in there taking action. Some people ran in from the sidewalk and I just followed... everybody just pulled it together pretty quick."

Fire officials say the flames started in the kitchen of one of the second-floor apartments, and that 12 units responded to the scene. 

Firefighters say everyone inside the building's four apartments managed to get out safely, and that the five people who were injured are expected to be OK.

The owner of the building told News 12 that the building will be boarded up until he hears from insurance. The exact cause of the fire still remains unknown.