A freight train carrying flammable and toxic gas derailed and caught fire in Blount County, Tennessee, Thursday, prompting the evacuation of more than 5,000 people. According to local officials, seven emergency workers were hospitalized after being exposed to chemical-laden fumes from the blaze. Blount County firefighter Kermit Easterling said that specialists advised firefighters to let the fire burn itself out because attempts to extinguish it could be hazardous. Residents within a three-kilometer radius were evacuated, the Federal Railroad Administration said. The derailed car carried acrylonitrile, a product used in the manufacture of plastics, rail company CSX Corp spokesperson Kristin Seay said. Officials said that people would be evacuated for at least 24 to 48 hours.