Congressional hearings are slated for next month and federal investigations will be conducted. Huntsman has already appointed a special Mine Safety Commission to look at the safety of all of Utah's mines and wants an independent investigation into the Crandall Canyon Mine disaster.

Sen. Mike Dmitrich, D-Price, said the letter could be a sign that emotions have gotten too high on all sides.

"I think Mr. Murray ought to face the fact that (the federal Mine Safety and Health Administration) is going to investigate and the state's going to be alongside them," he said.

Dmitrich was recently appointed to the governor's commission. He said Murray's threat about jobs may not amount to much.

"I don't think he has that many employees," Dmitrich said, referring to the 700 jobs Murray said were in danger. "I'm sure they'd want to work in a safe environment."

The families of the six trapped miners are now letting a union represent them in any talks about rescue and recovery efforts. On Friday, the United Mine Workers of America served the federal Mine Safety and Health Administration and Murray Energy Corp. with papers outside the Crandall Canyon Mine, putting them on notice.

"We would be designated as miners' representatives for the purpose of any discussions of rescue operations or recovery efforts," said UMWA spokesman Phil Smith.

A similar thing happened during the Sago Mine disaster in West Virginia. Murray has repeatedly lashed out at the labor union, accusing them of spreading rumors, misinformation and trying to unionize the non-union Crandall Canyon Mine.

The UMWA refused to say who signed the papers, fearful of recrimination by mine officials.

"They're concerned about repercussions, as are we," Smith said.

Local union reps told the Deseret Morning News earlier this week that all six families had signed the consent forms. Relations between Murray and the families have frozen since he announced that he would not continue the rescue effort because of the danger involved to others.

'Leave No Man Behind'

Mine officials and MSHA representatives met Friday afternoon at Murray Energy Corp.'s West Ridge Mine to go over safety plans for other mines the company runs in Utah, said Rep. Brad King, D-Price.

During a briefing Friday afternoon with the families of the trapped miners, King said they were told drilling had stopped for some time Friday because of the condition of the mountain.

"They are understandably distressed, but they are very good people. They still have faith and hope that some good will happen, but of course they know time is of the essence," he told the Deseret Morning News. "They know this is an industry where there is a possibility you don't come home at night. Those mines are regulated and regularly inspected, and you just expect when the mine is inspected they do a thorough job."