Just before 23:00, Engine Company 41 was dispatched to N College St for an odor of something burning inside a structure. Engine 141 requested Truck 45 to respond. Headquarters dispatched Truck 45 to the scene and Engine 245 responded in addition. Units arrived shortly thereafter and began investigating. Interior crews confirmed that they detected an odor along with the occupant but could not put a label on it. The resident stated that they have been trying to locate the source of the odor for approximately 3 hours with no success. The odor led crews to the back bedroom on the second division where it was the strongest. Crews investigated the odor for approximately 45 minutes before going available at 23:52.