St. Clairsville, Ohio • Robert Murray, the board chairman of the largest privately owned U.S. coal operator with extensive holdings in Utah, who long fought federal regulations to reduce black lung disease, died at his home in Ohio less than a week after announcing his retirement, a lawyer said.

Michael Shaheen, an attorney who had recently represented Murray, 80, told The Intelligencer/Wheeling News-Register that he died Sunday morning in St. Clairsville.

No official cause of death was given. Public reports recently stated Murray had applied for black lung benefits with the U.S. Department of Labor. The application said Murray was heavily dependent on oxygen.

Murray had announced his retirement Oct. 19 from American Consolidated Natural Resource Holdings Inc., which is based in St. Clairsville. The company has active mines in Alabama, Kentucky, Ohio, West Virginia and Utah. Murray was the founder, president and CEO of the company’s predecessor, Murray Energy.

Launched in 1988, Murray Energy began acquiring or developing Utah mines in 2006 and eventually operated several in Carbon County, including one that collapsed in 2007, killing six minors. Rescue efforts at the Crandall Mine claimed three more lives and caused six more injuries. The company recently emerged from federal bankruptcy protection, with its Chapter 11 plan becoming effective last month.

“Bob fought through his medical challenges with the same energy, drive, guts, and faith in God as he approached everything in life,” Gov. Mike DeWine, a Republican, said in a statement. Murray was a friend for three decades, DeWine said.

Murray had fought federal mine safety regulations for years, with his company suing unsuccessfully in 2014 over regulations to cut the amount of coal dust in mines to reduce the incidence of black lung disease.

Following the Crandall Canyon tragedy, federal regulators concluded the mine had been inadequately designed and had been operated in violation of its approved mine plan, further weakening its structure, and information signaling potential danger was withheld.

An investigation led to a $1.6 million fine against Murray subsidiary Genwal Resources Inc., the largest fine ever levied in a U.S. coal mining disaster. The company later agreed to $500,000 in additional fines after pleading guilty two criminal counts associated with the mine collapse.

Murray subsidiaries also operate Utah’s active Lila Canyon mine and idled West Ridge and Centennial mines.

Shaheen said a private memorial service for Murray was scheduled for Tuesday.

“Saddened to learn of the passing of Bob Murray,” tweeted U.S. Sen. Shelley Moore Capito, a West Virginia Republican. “He was a staunch ally for coal miners, a good friend, and a one of a kind person.”