The lawsuit filed Wednesday in 3rd District Court contends Cleveland-based Murray Energy Corp. and its affiliates continued to mine using a risky technique last summer, despite a mountain "bounce" in March 2007.
"It was a preventable tragedy," Colin King, one of several attorneys representing the families, said at a news conference Wednesday. "They were gambling with the safety of the miners."
A thunderous collapse, so powerful it registered as a 3.9 earthquake, trapped the men in the mine on Aug. 6. Their bodies remain entombed there. Three other men were killed 10 days later trying to tunnel in to rescue the miners.
Court papers contend the March 2007 bounce - a violent ejection of rock and coal from the mine's ribs, roof or floor - was ample evidence of the danger. It accuses Ohio-based Murray Energy and others of being "motivated by avarice and greed at the expense of safety and human life" in continuing to extract coal.
Murray Energy Vice President Rob Murray did not immediately respond to a message from The Associated Press seeking comment.
Murray Energy purchased Crandall Canyon in August 2006 and shares ownership with Intermountain Power Agency, a utility consortium comprised of about two dozen Utah municipalities, and the Los Angeles Department of Water and Power.
IPA and LADWP are also defendants in the lawsuit.
Thirty pages of court documents detail a string of decisions by Murray Energy and its associated companies at Crandall Canyon to conduct "retreat mining," which involves yanking supporting pillars of coal from inside the mine and letting the roof collapse as miners and equipment work their way out.
In a report released Monday, Elliot Lewis, assistant inspector general for the U.S. Department of Labor, said MSHA was negligent in approving a faulty roof-control plan for Murray Energy Corp. The report questioned the agency's approval for retreat mining.
In the same report, MSHA director Richard Stickler disputed that his agency was negligent or that it was unduly influenced by the mine operator.
The families of the miners - Kerry Allred, Don Erickson, Luis Hernandez, Carlos Payan, Brandon Phillips and Manuel Sanchez - are the plaintiffs in the lawsuit, along with two injured rescue workers and their families. The lawsuit seeks an unspecified amount of money.
Other defendants in the lawsuit are Murray Energy affiliates UtahAmerican Energy, Andalex Resources Inc., and Agapito.