“Initial reports indicate the cause of the incident was a fall of roof and rib on the 12 East longwall face,” West Virginia Office of Miners' Health, Safety and Training said.

“Three miners were involved. Forty-five-year-old assistant longwall coordinator John M. Garloch was fatally injured, and two other miners were injured and transported to local hospitals for treatment. One of those miners has been released; the other remains hospitalised.

Investigations are ongoing. There were five mining fatalities in WV last year.

Murray acquired McElroy and four other underground coal mines in the state off Consol Energy under a $US3.5 billion ($A4.6 billion) deal struck in late 2013. As of last month these mines were collectively targeting 38 million tons of output, according to Murray.