Robert Murray, whose Murray Energy Corp. owns the Emery County mine, also acknowledged: "I don't know whether these miners are alive or dead, only the Lord knows that."

After the failure of Monday's efforts to tunnel through to the six from a parallel shaft, Murray also said it now appeared rescue would not occur until week's end. Among the several methods being used to reach the miners is the helicopter-aided drilling of a two-inch wide shaft through which listening devices can be dropped and air pumped.

"It will take three days, if everything goes right, to get to these miners. . . . At that time, we will know if they are alive or dead."

He said that rescuers were bulldozing a mountain path to erect a seismic listening device outside the area where miners are believed trapped, hoping to establish contact. Once the device is in place, crews will set off dynamite, a sign to the stranded men to tap the ceiling with hammers.

Murray, his voice occasionally breaking, also again insisted it was an earthquake -- not his mine's operations -- that had triggered the cave in early Monday morning. Scientists at the University of Utah Seismograph Stations have suggested their sensors' 3.9-magnitude reading actually was caused by the cave-in.

"This was caused by an earthquake, not something that Murray Energy . . . did," the mining magnate declared. "It was a natural disaster, an earthquake. . . . There seems to be a lot of speculation by some of you in the [news] media that this was not an earthquake."

Richard Strickler, assistant director of the federal Mine Safety and Health Administration, said at an afternoon news conference that it was too soon to say if there was an earthquake, "but MSHA will answer that question. He said after the rescue operation, his agency will conduct an accident investigation that will determine the cause of the collapse.

Murray repeatedly interrupted his morning news conference, which had already started more than 90 minutes late, to demand that a news helicopter overhead be ordered out of the area by law enforcement officials.

He also chastized the Associated Press, Fox News and others for what he insisted was inaccurate reporting, based on comments from "lackeys" for those trying to unionize his non-union mine.

Specifically, some accounts have suggested the mine was using the so-called "retreat" method of recovering coal. In that method, pillars of coal are used to hold up an area of the mine's roof. When that area is completely mined, pillars are pulled to get access to useful coal, causing an intentional collapse. Experts say it is one of the most dangerous mining methods.

Murray steadfastly denied that method was in use by the trapped miners.

Asked about it at an afternoon news briefing, MSHA's Strickler said the mine has had retreat mining, but he couldn't say if the trapped workers were engaged in that method or even if past retreat mining could have led to the collapse.

It was a grimmer Murray who addressed reporters today after meeting with families of the trapped miners.

"I've had men die in my arms. I've been trapped in mines," he said, noting he had spent half a century in the coal mining business. "There are two scenarios. . . . The shock of the earthquake and the concussion killed them, that's one scenario. The other scenario is that they are very much alive and we are going to rescue them."

Murray vowed that, "I will not leave this mine until there has been a rescue, dead or alive."

Earlier Tuesday, Emery County sheriff's deputies were seen and heard warning miners coming off shift not to talk to reporters. However, one miner, Carl Grissman of Price, acknowledged rescuers were becoming increasingly worried about the fate of their colleagues trapped inside the Crandall Mine.

"It depends on who you talk to," he said when asked what crews' mood was. "I would not say good," he added, when asked his own feelings on the progress of rescue efforts.

Julie Jones, a Huntington city councilwoman whose son, Elam, is involved with the rescue efforts, said her son told her late Monday that "miners were down on their knees digging with their hands to get those guys out.

"He says, 'It's scary, Mom. But I have to be with them; I have to do my job,'" Jones added.

As many as a dozen mine rescue teams continued to work on various schemes to reach the miners today.

Late yesterday, through, the most promising approach to retrieving the miners failed. Rescue workers had breached a seal on an old tunnel Monday afternoon they hoped would bring them within 100 feet of the miners. But their attempt to take a parallel tunnel deep into the mountain and then cut across the soft coal wall had to be scrapped when workers found multiple areas where the parallel tunnel had caved in.

It marked a dispiriting end to a day that began early Monday, when the collapse sent four miners scurrying for their lives and left six others trapped about 3.4 miles and 1,500 feet deep from the mine entrance. The workers have not been heard from since 2 a.m. Monday.

Murray, CEO and president of the Murray Energy, acknowledged the setback but insisted he remains hopeful.

"Progress has been too slow, too slow," Murray said today. "We've only moved 310 feet closer to these miners from where we started. We only achieved 50 feet [Monday night] because of geotechnical problems and technical problems that forced us out of the mine."

Four of the trapped miners are Latino, three of those Mexican, said Mexican Consulate Salvador Jemenez, who also was at the scene today to confer with mine officials.

"We want to make sure they do everything to bring them back safe," he said.

The Associated Press contributed to this report