A 71-year-old man died in a house fire in Biddeford on Monday afternoon.

The victim, who Biddeford police and fire departments would not identify, was found unconscious inside a second-floor apartment above a two-car garage, which is attached to a single-family home at 289 Alfred St., near the intersection of Alfred and Ray streets.

No one else was in the home, Biddeford Fire Department Chief Lawrence Best said.

Multiple fire units responded to the heavy fire around 3 p.m. Monday, which appeared to be coming from the apartment unit. First responders tried to resuscitate the man, but he did not survive. The fire was under control in about an hour.

The apartment building was badly damaged and “will be uninhabitable,” according to the Biddeford Fire Department. The main house was not damaged, according to the state Fire Marshal’s office.

The man’s cause of death is under investigation by the Biddeford Police Department, and the cause of the fire is being investigated by the state fire marshal’s office.