A worker was injured after a fire broke out at a Madisonville residence Wednesday. Madisonville Fire Department responded to 619 South Madison Avenue just before 11:00am. The homeowner told them employees with a heating and air company were working on a natural gas line that was connected to a floor furnace. The line was not shut off and a spark caused a flash fire from the natural gas build up in the crawl space. The fire was extinguished prior to the fire department’s arrival. One employee was transported to RegionalMedicalCenter for burns he sustained.