At least 21 people were displaced from their home in Bushwick Friday morning following a three-alarm fire at an apartment building on Montrose Avenue.

Fire officials say the fire started on the second floor of 236 Montrose Ave. before spreading to a third floor and neighboring apartment building.

Five people, including three firefighters, suffered injuries not considered life-threatening.

The Red Cross is assisting the affected tenants. The FDNY is investigating what sparked the fire.

One witness described the fire as an “explosion” that was followed by flames that rushed to the roof.

A tenant named Brandon told News 12 that his grandmother owns the building, which has been in the family for at least three decades.

"It's heartbreaking…Things happen for a reason though,” he said. “I just try to be positive about everything. I'm glad we're safe and nobody's dead or really badly injured right now that I know of."