Engine 1 was first to arrive on scene and reported heavy smoke coming from a HVAC unit in the rear of the building. Firefighters gained access to the large HVAC unit and tried to pinpoint where the smoke was coming from. After disconnecting gas and power to the unit the smoke did not stop. Upon opening the front door, crews were confronted by heavy smoke conditions. Engine 1used positive pressure ventilation to remove smoke from the building. Firefighters heard water running in the kitchen area and found an extinguished fire in area of the Ice machine. The fire had melted a water line near the filtration system and had apparently extinguished the fire. Ongoing ventilation efforts were made with the assistance of Ladder1. Engine1 believes that a fire started near, or in the ice machine,…..