At ~5:01 PM, Westmoreland 911 dispatched Station 20 (Murrysville VFC) for an Automatic Fire Alarm (AFA) at a home on Treeline Drive. Station 20 responded with Truck 20 (4 firefighters), with Assistant Chief 20 and Sergeant 20 going directly to the scene, and 2 additional firefighters (including Captain 20) on standby at the station ready to crew Engine 20. Westmoreland 911 also dispatched the following stations to support Station 20: Station 22 (Export VFC), Station 64 (White Valley VFC), and Station 78 (Sardis VFC). Assistant 20 arrived on scene, established command, and found no smoke or fire coming from the secured structure. Once a keyholder arrived, Asst. Chief 20 and Sergeant 20 entered the structure, found no evidence of fire or smoke, determined that the AFA System had malfunctioned, and Command 20 cancelled all responding stations. Command 20 assisted the keyholder in resetting the AFA System. Truck 20 returned to service and station.