Around 5:30pm, the first alarm assignment was struck for the Dress Barn in the Cranberry Mall for smoke in the building after a power surge. Engine 42 marked en route quickly and arrived with Ladder 21, both taking position on the alpha side of a strip mall. Chief 21 directed both crews inside for investigation along with Chief 21-2. Crews had a moderate smoke condition inside coming from the HVAC vents. Towers 42 and 21, along with ladder 22 took the roof to investigate. Crews determined a malfunction with the roof top unit and controlled the power.