A malfunctioning exhaust fan apparently caused a fire Friday afternoon at Sonny’s Pizzeria at 43 Madison Avenue in Sturgeon Bay. Shortly after noon, the Sturgeon Bay Fire Department sent four vehicles and seven firefighters to the popular waterfront restaurant after flames were seen coming out of the chimney on the roof’s edge. During a search of the building’s attic, intense heat of about 500 degrees was encountered. It quickly became obvious that there was no fire on the inside of the building and that the problem was related to the operation of the firm’s wood-fired pizza oven and the fan outside. For some reason, the exhaust system stopped working and the heat from the wood-fired pizza oven could not be dissipated. Crews used a couple of fire extinguishers on the exterior exhaust system and removed the equipment. There was no danger to the people having lunch and the indoor activities at the restaurant were not disrupted. There was some damage to the exhaust equipment and the wood-fired oven will be out of commission until repairs are affected. As a precautionary measure, two ambulances responded to the scene, but there were no injuries. Fire crews cleared the scene at 1:11PM.