Officials defend rescue efforts after 5 tunnel workers are killed

When fire broke out deep underground at a hydroelectric plant in the Rockies, officials at the surface dropped a radio to five trapped men in a tunnel and were relieved to learn they were OK.

But by the time emergency crews reached them six hours later, they were dead.

On Wednesday, a day after the tragedy more than 1,500 feet below Xcel Energy Corp.’s Cabin Creek power plant, investigators struggled to figure out what went wrong as crews began to remove the bodies.

It was unclear whether the five maintenance workers were burned, suffocated or overcome by fumes from the highly flammable epoxy sealant they were using to coat the inside of a 12-foot-wide water pipeline.

Authorities defended their efforts, saying smoke, the complexity of the 4,000-foot-long tunnel’s design and uncertainties about the dangers prevented them from going in for more than 3 1/2 hours after the fire started.

“We didn’t know what was causing the fire, what was feeding the fire,” Undersheriff Stu Nay said.

The blaze erupted when a machine used by the workers to coat the tunnel caught fire, Xcel Energy spokeswoman Ethnie Groves said.

Nine employees of RPI Coating of Santa Fe Springs, Calif., had been sealing the inside of the pipe to prevent corrosion. The tunnel delivers water from a reservoir to electrical turbines at the plant 30 miles west of Denver.

The smoldering fire broke out about 1,400 feet from the tunnel’s bottom and was reported around 2 p.m., authorities said.

Four RPI workers escaped from the tunnel and were treated at a hospital and released. Five others scrambled about 1,000 feet above the fire but were trapped by smoke and a steep spot where the tunnel’s slope goes from 15 to 55 degrees, Nay said.

Officials dropped a radio to the workers, who reported around 2:40 p.m. that they were uninjured, Nay said.

Rescuers also dropped breathing masks and air tanks into the tunnel but were unsure if the workers were able to find them or use them, Nay said. Powerful fans drove air into the tunnel to clear it of smoke so the workers could breathe.

Alpine rescue team rappellers prepared to enter but were called off for fear of toxic fumes and because it would be difficult to get the victims out through the steeply pitched top end of the tunnel, Nay said.

A crew trained in confined-space rescues and firefighting began making its way through the smoke in the tunnel at 5:40 p.m., officials said. At 8:10 p.m., the crew reached the men, discovered they were dead, and retreated, Nay said.

The California-based contractor that employed the victims was cited and fined in the past for safety violations involving two deaths and several injuries, a California safety official said Wednesday.