Investigation Report: Xcel Energy Hydroelectric Plant Penstock Fire

On October 2, 2007, a chemical fire inside a permit-required confined space1 at Xcel Energy‘s hydroelectric plant in a remote mountain location 45 miles (72 kilometers) west of Denver, Colorado, killed five and injured three workers. Industrial painting contractors were in the initial stages of recoating the 1,530-foot (466-meter) steel portion of a 4,300-foot (1,311-meter) enclosed penstock2 tunnel with an epoxy coating product when a flash fire occurred. Flammable solvent being used to clean the epoxy application equipment in the open penstock atmosphere ignited, likely from a static spark. The initial fire quickly grew as it ignited additional buckets of solvent and substantial amounts of combustible epoxy material, trapping and preventing five of the 11 workers from exiting the single point of egress within the penstock. Fourteen community emergency response teams responded to the incident. The five trapped workers communicated using handheld radios with co-workers and emergency responders for approximately 45 minutes before succumbing to smoke inhalation.