Oct. 2, 2007, Cabin Creek, Georgetown, Colo.: Nine industrial painters were recoating a portion of penstock tunnel that runs 1,530 feet deep into the remote mountainous area surrounding the Xcel Energy Cabin Creek hydroelectric station. Inside the confined area, the workers used a highly flammable solvent to clean their equipment, which filled the tunnel with flammable vapor. The vapor ignited and the resulting explosion separated the nine workers -- blocking five of them from the only egress point by a wall of fire. Despite lengthy rescue attempts, the five workers were asphyxiated as smoke slowly filled the tunnel.