At ~ 7:28 PM, Westmoreland 911 dispatched Station 20 (Murrysville VFC) to assist Station 90 (Forbes Road) for a report of a smoking heating unit at the AMC Classic Delmont 12 Cinema. Station 20 responded with 5 firefighters (including Assistant Chief 20) going to the station to crew Engine 20, which was dispatched on the fill, while Chief 20 proceeded directly to the scene. Westmoreland 911 also dispatched the following stations to support Station 90: Station 22 (Export VFC), Station 30 (Delmont VFC), Station 59 (Slickville VFC), Station 63 (Claridge VFC), Station 64 (White Valley VFC), Station 65 (North Hempfield VFC), Station 87 (Harrison City VFC), and Station 106 (Grandview VFC). Station 90 and 64 units arrived on scene and command was established by Chief 90 with an evacuation in progress. Upon investigation, crews found and shut down the defective heating unit. Command 90 determined that sufficient fire/rescue resources were at the scene, and cancelled all units not on scene including Engine 20. Engine 20 returned to service.