A woman was killed Saturday night in a West Islip house fire, authorities say.

An investigation is underway into the cause of a fire that killed a woman inside the home at 122 Myrtle Ave. at around 7:45 p.m. 

Neighbors say they saw flames shooting from the back of the house and spread quickly.  

About 125 firefighters responded to the fire. Neighbors tell News 12 that firefighters made a valiant effort to save the woman. 

“Our teams on scene made an aggressive search,” says West Islip Fire Department Assistant Chief Robert Celeste. “Unfortunately, the victim died on scene.” 

Celeste says they are turning the scene over to Suffolk police and the homicide squad to investigate. 

Police say a preliminary investigation has determined the fire as noncriminal.

Police say the identity of the victim will be confirmed by the Suffolk County Medical Examiner.