The families of coal miners killed or injured inside Utah's Crandall Canyon Mine said they are planning to file lawsuits against two power agencies involved in operations.

The Los Angeles Department of Water and Power and the Utah-based Intermountain Power Agency should have known that dangerous conditions inside the mine would put workers at risk and lead to deaths, attorneys for the families said.

Intermountain Power, whose members are municipal utilities, is co-owner of the mine, and the Los Angeles utility has a management role.

Both "caused or permitted mining activities to take place within the mine in an unreasonably dangerous and negligent manner," attorneys said in letters notifying them that lawsuits will be filed in federal court.

The lawsuits will seek unspecified damages for pain, suffering, loss of wages and other benefits. Six miners more than 1,000 feet below ground died after the walls of a shaft imploded Aug. 6. Their bodies have not been recovered.

Ten days later, during an attempt to tunnel toward the group, three men died during another collapse. The mine is in Emery County, about 120 miles south of Salt Lake City.

Under California and Utah law, a governmental entity must receive notice of a lawsuit. The letters were dated Tuesday and Wednesday.

The Los Angeles agency has 45 days to respond, and Intermountain Power has 60 days to respond, before a lawsuit can be filed, said Ed Havas, an attorney for the families.

Mine co-owner Murray Energy Corp. of Ohio and others also will be named as defendants, Havas said.

An attorney for Intermountain Power could not immediately comment on the notice, and a telephone message left for the risk management department of the Los Angeles agency was not immediately returned.

Two dozen survivors of the dead miners and two men injured during rescue efforts will be plaintiffs in the lawsuit.

The families of miner Dale Black and federal inspector Gary Jensen, who both died in the second cave-in, are not part of the case at this time, Havas said.

Efforts to recover bodies from the mine ended Aug. 31. The shaft has been walled off with cinderblocks.