Fire officials say one person is dead following a house fire Saturday night in West Islip.

Firefighters said they received a call at 7:45 p.m. about large fire on Myrtle Avenue.

Neighbors told News 12 Long Island that the fire seemed to have started in the rear of house and then quickly spread.

About 125 firefighters from multiple departments responded. Officials said fire crews performed an interior attack of the building and got most of the fire under control when they found the victim inside the house.

West Islip Fire Department Assistant Chief Robert Celeste said there was heavy fire in front and along the side of the house when crews arrived.

Celeste said teams searched aggressively for the victim upon hearing reports of an occupant inside.

Upon finding the victim, Celeste said firefighters then put out the fire entirely and then turned the scene over to Suffolk police and the homicide squad.

The cause of the fire is unknown.

The Suffolk County fire marshal is also investigating the incident.