At 11:23 PM, Westmoreland 911 dispatched Station 20 (Murrysville VFC) to assist Station 59 (Slickville VFC) for an Automatic Fire Alarm (AFA) at Mitsubishi Advanced Chemical Materials on Industrial Drive in Salem Township. Station 20 responded with Truck 20 (3 firefighters including Captain 20). Westmorland 911 also dispatched the following additional stations to support Station 59: Station 64 (White Valley VFC), Station 22 (Export VFC), Station 30 (Delmont VFC), Station 90 (Forbes Road VFC), Station 87 (Harrison City VFC), and Station 63 (Claridge VFC). Engine 59 with first on scene, with Chief 59 establishing command, and the night shift evacuating the structure. Command 59 coordinated the placement of the arriving units, with Truck 20 being put into the staging area with its crew reporting to the command post. Interior firefighter crews from Engines 59, 64, and 90 entered the structure; and found that the AFA System had activated when a water riser for the fire suppression sprinkler system had broken. With no fire in the structure, Command 59 released Truck 20 for return to service and station.