GEORGETOWN, Colo. -- Five workers who were trapped deep underground by a chemical fire at the Cabin Creek hydroelectric facility have been found dead, authorities confirmed Tuesday evening.

The fire, which broke out inside a water pipeline while the workers were applying epoxy to it, was extinguished Tuesday night by fire crews called in from the Henderson Mine. When the smoke cleared, the 12-man crew moved up the shaft and that's when they found the bodies of the trapped workers.

"Once they made sure there was plenty of air inside for the rescuers, we sent people in and were able to locate bodies from the trapped parties," said Clear Creek County under sheriff Stu Nay.

The men who died did not work for Xcel Energy but were contractors hired to do maintenance work on the plant.

"At this point, we don't know who they are," said Nay.

Nay said the next of kin had not yet been notified of the deaths. Crews will be working through the night to recover the workers' bodies, said to be at least 1,000 feet underground.

"We want to express our deepest sympathies to the families, friends and co-workers of those who died," said Tim Taylor, president and CEO of Public Service Company of Colorado and Xcel Energy Company. "We are deeply saddened to hear of their deaths and our sympathies go out to the families, and that is where our thoughts should be."

The coroner will determine how the workers died and an investigation is already under way to determine what happened and why.

"Certainly, we'll be working closely with the authorities to investigate what happened. We're going to keep the lines of communication open between Xcel and the agencies working on this investigation, and we'll be working closely with the agencies as the investigation proceeds," Taylor said. "We're always concerned with safety. It is one of our core values at Public Service Company and Xcel."

Authorities will update the public on the recovery effort at a 9 a.m. news conference Wednesday.

Chemical Fire Separates Workers, Traps 5 Men

Nine contractors were working inside the empty water tunnel, about 1,500 to 2,000 feet below ground, coating it with an epoxy solution to prevent corrosion, when a piece of equipment ignited the fire, Xcel spokeswoman Ethnie Groves said.

The fire separated the nine men inside the 48-inch wide shaft, also known as a penstock. A penstock is a tube is used to transfer water from a lake to the turbines inside the plant.

The four workers below the fire were able to escape, but five workers above the fire were trapped, Groves said.

About 40 minutes after the fire broke out, the trapped workers made radio contact with authorities and told them that they were not injured. But that was about 3:30 p.m. and they were never heard from afterward.

The chemical fire created smoke inside the pipeline but officials believed that the workers were able to breathe because crews above ground had dropped oxygen bottles and masks to the workers, Groves said.

"They did lower down a tube with fresh air and masks shortly after (the fire) occured. We cannot confirm if they received those or not," Groves said.

The trapped workers were hunkered down on a temporary platform used to stop water from coming up the pipe while the workers conducted maintenance.

Rescue crews had planned to rescue the workers in two steps. First, Henderson Mine crews trained to fight fires and rescue people in a confined space would come up through the bottom of the pipeline to extinguish the fire.

Then after the fire was extinguished, members of the Alpine Rescue Team would rappel down the tunnel from the top and rescue the workers.

The trapped workers did not have the necessary equipment to climb up the pipe. Groves said they would have had to climb about 1,500 feet and then go up a 50-foot vertical rise to reach the surface.

Of the four workers who escaped, two were treated for chemical inhalation and one was airlifted to St. Anthony's Central Hospital. Their names have not been released.

About 50 rescue vehicles gathered on site to assist with the rescue and stayed there most of the afternoon as the rescue effort turned into a recovery effort.

The Cabin Creek Power/Hydro Plant, six miles up Guanella Pass Road from Georgetown, is a hydroelectric pumped storage power plant owned and operated by Xcel Energy.

The plant opened in April 1967 and it comprises of two reservoirs where water flows from an upper reservoir to a lower reservoir to turn its generators and create electricity.

The hydroelectric plant generates electricity during peak times of demand by releasing water from one reservoir into a lower reservoir, then pumping the water back to the upper reservoir during non-peak times.

The plant is located at 10,018 feet above sea level and produces 234 megawatts of power.

Xcel Energy said that it was a supplemental power plant and no electrical outage is expected by the shutdown of the plant and the rescue operation.