Watertown Fire Rescue was called 2235 Air Haven Road for a chimney fire. Upon our arrival fire was found inside the house around the area of the chimney and smoke was coming from the attic space. An interior attack was performed and fire inside the house was knocked down. Prior to the knock down fire had entered the attic space of the house. After several attempts to extinguish the attic fire, the structure became unsafe for firefighters to continue interior operations. WFR personnel began an exterior attack of the fire. Later an attempt to re-enter the structure was unsuccessful due increasingly dangerous conditions. Firefighters remain on scene to overhaul the house. Watertown Fire Rescue was assisted by Codington County Sherriff’s Office, Florence Fire Department, Castlewood Fire Department, and Codington County Search and Rescue.