At ~ 12:53 PM, Westmoreland 911 dispatched Station 20 (Murrysville VFC) for an Automatic Fire Alarm (AFA) at Marquis Place. Station 20 responded with Truck 20 (3 firefighters), with 2 firefighters (including Assistant Chief 20) going directly to the scene. Westmoreland 911 also dispatched the following stations to assist Station 20: Station 22 (Export VFC), Station 64 (White Valley VFC), Station 78 (Sardis VFC), Station 87 (Harrison City VFC), and Station 610 (Murrysville Medic One). Assistant Chief 20 was first on scene, established command, found no smoke or fire coming from the structure, and that the structure was being evacuated. Engines 22 and 64 arrived on scene, the firefighters entered the structure, and found that a AFA Pull Box had been accidentally activated. Command 20 returned all responding units, the structure's AFA was reset, and the occupants were allowed to return. Truck 20 returned to service and station.