"These folks are very strong," he said. "They're as good a group as I've ever seen."
Despite the setback, Murray said he remains optimistic that the men trapped in the Crandall Canyon coal mine will be rescued alive.
"We have no idea whether the damage in the mine extended to the area where the miners are," he said, noting rock and coal could have crushed them during the collapse but saying he hoped that it had sealed them off in a large space with plenty of air.
Murray described the area where the men were working as having 8-foot ceilings, and an 18-foot width, with a "comfortable" temperature of 58 degrees. The miner's only source of illumination would be the lamps attached to their hard hats, and they're trained to use them sparingly so they can extend the amount of time they'll have with light in an otherwise pitch-dark space.
Rescuers are now focusing on the 1,700 feet of tunnel between the rescuers and the area where the miners were working. Murray said he does not know if the rubble extends the entire 1,700 feet.
"We'll get them back," he said, "but it may be as much as three days."
Most of the work is being done by heavy machinery, Murray said. A steady stream of equipment moved into the mine all day.
"We're sparing absolutely no expense to get the machinery that we need here," Murray said.
Along with rescuers working inside the mine, Murray described three different efforts to reach the miners from the outside. A helicopter will help aim a large drill on the top of the mountain so it can drill down.
That method will take three days to reach the miners, Murray said.
Bulldozers are cutting roads for a second drill that might reach the miners in two days, Murray said.
Another drill is boring horizontally to the mine but there was no timetable on when that might be finished.
Murray said any effort will take at least two days to reach the miners.
"We will be here on our feet until we get these men out one way or the other," Murray said.
Murray said the six men range in age from 20s to late 40s. They all are from the area, he said, and all "are family men."
Murray said he has advised families of the men not to speak with reporters.
"There's apprehension right now. We don't know if they're dead or alive," Murray said. "We'll go up there ad we'll rejoice, or we'll go up there with a tragedy."
-- Tribune staff writers Russ Rizzo, Jason Bergreen, Greg Lavine, Glen Warchol, Chris Smart and Paul Beebe contributed to this report.