Initial dispatch came in as one call reporting the house adjacent to 403 Sigourney was on fire. As units started responding fire alarm started recieving multiple calls and Engine 5 reported smoke in the air from a distance and called a working fire. When Engine 5 got on scene they found heavy fire showing in the back of the vacant house. Minutes after being on scene the 2nd alarm was transmitted. About an hour into the fire command reported the fire knocked down.