A two-story home with an attached garage was destroyed by a fire at 145 Maranacook Road in Winthrop on Thursday afternoon. The fire appeared to start in the garage, where a pig was living and heat lamp had been operating, said Dan Brooks, chief of the Winthrop Fire Department. A member of the state fire marshal’s office is coming to the home to determine the precise cause of the fire. A mother and son who lived in the home noticed the fire and got out safely, as did the pig and at least one dog, Brooks said.