The cause of a house fire in Madisonville that occurred early this (Tuesday) morning is under investigation.
            Madisonville Fire Department responded to 129 Forest Lane just a little after midnight.
            No one was home at the time of the fire.
            Medical Center Ambulance Service was called to treat a firefighter who was overcome by the heat, as well as a Madisonville Utilities worker who experienced a medical emergency.
            Fire crews say there was substantial damage to the structure and contents in the home.