Chilmark firefighters quickly quelled a small fire at Blue Heron Farm early Tuesday morning. Chilmark fire chief David Norton said the call came in at 3:30 a.m. from an automatic fire alarm in the farmhouse. The fire was in the wall of the main house near a porch that had a gas grill on it. Firefighters had the fire out within a matter of minutes, Mr. Norton said. “Very small, very contained, extinguished quickly,” the fire chief said. He said the cause of the fire was the gas grill.