At ~9:09 PM, Westmorland 911 dispatched Station 20 (Murrysville VFC) to assist Station 78 (Sardis VFC) for an Automatic Fire Alarm (AFA) at Respironics on Murry Ridge Lane. Station 20 responded with Truck 20 (5 firefighters including Lieutenant 20), with 2 additional firefighters at Station 20 in case additional units were needed at the scene. Westmorland 911 also dispatched the following stations to assist Station 78: Station 102 (Washington Twp. VFD), Station 115 (Lower Burrell VFD), Station 183 (Renton VFD), and Station 236 (Holiday Park VFD). Engine 78 was first on the scene, with no fire or smoke evident, and Chief 78 established command of the scene. Upon Truck 20's arrival on scene, Chief 78 directed that Truck 20's crew set its 100 foot Platform Ladder to inspect the structure's Rooftop Heating and Cooling Units (RTUs). Upon inspection of the RTUs, Truck 20's crew found no defective/malfunctioning RTUs. Station 78 firefighters in concert with the other responding stations crews made entry into the structure. The interior search teams found no fire or smoke, however a malfunctioning smoke detector was discovered in the structure's elevator shaft. At that time Chief 78 released all on scene units including Truck 20, except for Station 78. Truck 20 returned to service and station.