BROOKLYN - Three firefighters and two residents were injured after a three-alarm fire at an apartment building in Brooklyn Monday.

It happened on Voorhies Avenue in Sheepshead Bay around 4 a.m. 

Neighbors credit a woman who knocked on their doors alerting them to get out of the building because it was on fire. 

The woman, who only identified herself as Kate, says everything may have been lost in the fire, but at least she and her neighbors are still alive. 

One woman says if not for Kate’s action, she and her young son would not be here. 

The Red Cross was on site assisting families who lived inside the building. 

Two firefighters and two occupants of the apartment building suffered minor injuries, but one firefighter suffered serious but non-life-threatening injuries, according to officials. 

Fire officials say they have not yet determined the cause of the fire, and they are still investigating.