At ~ 10:09 AM, Westmorland 911 dispatched Station 20 (Murrysville VFC) for an Automatic Fire Alarm (AFA) at Heritage Elementary School. Station 20 responded with Engine 20 (3 firefighters), with an additional firefighter at the station prepared to being additional apparatus to the scene. Also dispatched with support Station 20 was Station 610 (Murrysville Medic One). When Engine 20 and Medic 613 arrived on scene, the senior firefighter established command, and found no fire or smoke coming from the structure. Upon investigation, it was found that cleaning near a smoke detector had activated the AFA System. Command 20 released all responding units for return to service.