Albany Police said multiple people were shot late Friday night shortly after a person fired a flare gun into a residence, causing a fully engulfed structure fire.

Police said this incident occurred on Madison Avenue, near South Swan Street, around 10 p.m.

Around that time, someone fired the flare gun at a residence on the 300 block of Madison Avenue, causing it to catch fire and become fully engulfed.

Albany Fire told us the building that caught fire, 333 Madison Avenue, is a three-story structure. When the crews arrived, there was a heavy fire on the first floor, extending to the second and third floors.

After that, someone fired several rounds from a handgun. Police said four shooting victims were found at the scene.

Officials said a 17-year-old man was shot in the head, and is currently at Albany Medical Center in critical condition with life-threatening injuries, said Albany Police Chief Brendan Cox.

Police added three other victims were found with gunshot wounds to their legs: a 17-year-old man, a 62-year-old woman, and a 24-year-old woman. All victims were treated at Albany Medical Center for non-life-threatening injuries.

None of the victims lived at the building that caught fire, said Chief Cox.

Police said while emergency crews were taking the victims to the hospital, an ambulance struck a parked vehicle, causing the vehicle to strike a police officer, injuring his leg. Police tell us the officer is doing OK.

The Albany Fire Department shared with us that the fire was under control at approximately 12:13 a.m., about two hours after it began. There was also some damage to the adjoining building, 345 Madison Avenue.

Fire officials told NewsChannel 13 on Saturday morning that the fire had rekindled, and crews were working on cleanup. A one-story building was demolished on Saturday, and the home will be demolished on Monday.

The fire remains under investigation.