Stations 74, 81 and 2 were alerted for a commercial building fire at Wawa on Sussex Highway, at 20:15 hours. 74 Command arrived to find a light smoke condition inside the business. Engine 74-3’s crew went interior to investigate and found a malfunctioning heating duct. Salisbury Truck 2 arrived and laddered the C-side of the structure to evaluate the HVAC systems with negative results. Command then placed the situation under control. Units that responded were: Delmar 74 Command, Engine 74-3, Engine-Tanker 74-2, Rescue 74, Paramedic B-74, Salisbury Truck 2, Laurel Tower 81, Engine 81-2 and Sussex County EMS Medic 102.