At ~5:41 PM, Westmoreland 911 dispatched Station 20 (Murrysville VFC) for an Automatic Fire Alarm (AFA) at Maple Commons Shopping Plaza. Station 20 responded with Truck 20 (6 firefighters including Captain 20), with Chief 20 going directly to the scene, and 4 firefighters on standby at the station, in case Engine 20 was needed. Westmoreland 911 also dispatched the following additional stations to support Station 20: Station 64 (White Valley VFC), Station 22 (Export VFC), Station 78 (Sardis VFC), and Station 87 (Harrison City VFC). Chief 20 was first on scene, established command, and found that a cleaning accident had activated the shopping plaza's AFA System. Command 20 returned all responding units except for Truck 20. Upon Truck 20’s arrival, its crew used its "Knox Box" Key to gain entry to to the AFA system panel, and reset the system. Command 20 returned Truck 20 to service and station.