WASHINGTON -- Federal regulators on Monday proposed more than $1 million in penalties against the two companies involved in a fatal tunnel fire last year in Colorado.

The Labor Department's Occupational Safety and Health Administration proposed $845,100 in penalties against RPI Coating Inc. and $189,900 against Xcel Energy "for alleged serious and willful violations of federal workplace safety and health standards."

"This catastrophe could have been avoided if the companies had followed their critical safety procedures," Assistant Secretary of Labor for Occupational Safety and Health Edwin G. Foulke Jr. said in a release.

Xcel Energy operates the plant and RPI Coating Inc. was hired to apply an epoxy and paint coating to the inside of the tunnel.

Dick Kelly, chairman, president and chief executive of Minneapolis-based Xcel Energy, said the company needed more time to review the government's report, but added "we disagree with any statement that implies we acted without regard to the safety of our employees and contract workers."

A spokeswoman for Santa Fe Springs, Calif.-based RPI declined to comment.

The fire began on Oct. 2 at the Xcel Energy Cabin Creek hydroelectric plant in Georgetown, Colo., while employees were in a tunnel cleaning a sprayer with a flammable solvent. Vapor from the solvent ignited and five employees working deep inside the tunnel died from asphyxiation.

RPI received 13 willful citations with proposed penalties totaling $778,500. Three of the citations are for the company allegedly bringing unsafe electrical equipment into the tunnel. The other allegations include: not providing employees with adequate ventilation, not installing carbon monoxide alarms, not arranging for emergency response, providing inadequate chemical hazard training and a lack of fire extinguishers in the work area.

RPI also received 25 lesser citations with penalties totaling $66,600, according to OSHA.

Xcel Energy was issued two willful citations with proposed fines of $126,000 for failing to take precautions to protect employees from tunnel hazards and for not arranging rescue services. The company also received 19 lesser citations with proposed penalties totaling $63,900.

The companies have 15 business days to request an informal conference with OSHA's area director or to contest the citations and proposed penalties.

The workers were experiencing trouble with a spray gun used to apply the epoxy and paint mixture and were adding a solvent to a hopper used to warm up the mixture to liquify it for application. The hopper's heating element inadvertently turned on, igniting the vapors.

The five workers scrambled past a bulkhead used to keep their work area dry and radioed to their co-workers that they were OK, except for minor injuries, but fire blocked their downhill escape route. The 55-degree incline of the tunnel above them kept them trapped more than 1,500 feet below ground.

Then the radio went dead about an hour after the fire broke out.

The bodies, found scattered along a 200-foot length of the 12-foot-wide pipe, didn't have burn marks, indicating that the men probably died from the smoke and fumes from the chemical fire.

The dead workers were all from California and have been identified as Donald Dejaynes, 43; Sun City; Dupree Holt, 37, of Ontario; James St. Peters, 52, hometown unknown; Gary Foster, 48, of Bakersfield; and Anthony Aguirre, 18, of Mira Loma.

The Clear Creek Sheriff's Office released 911 calls about the fire, which were dramatic but didn't reveal any detail that hasn't been known.

In one tape, Bob McGurk, a Control Specialist at Cabin Creek is heard.

"We have a fire in our penstock, in our tunnel," he said. "I've got a chemical fire 1,000 feet underground ... There are people trapped."

Officials lowered breathing masks and air tanks and a spare radio to the men, but the smoke might have kept them from seeing the items.

Emergency crews reached the workers six hours later, about a half-mile from the tunnel's bottom exit.

Authorities have defended their rescue efforts, saying smoke, the complexities of the 4,000-foot tunnel's design and uncertainties about the dangers kept them from successfully entering the tunnel for more than 3 1/2 hours after the blaze broke out.

One crew went in about 1 1/2 hours after the fire broke out but had to turn back because of the smoke.

Four RPI Coating workers escaped from the tunnel, which delivers water from a reservoir to turbines that generate electricity at the plant 30 miles west of Denver.