Consol Energy spokeswoman Lynn Seay told ILN that one of its employees, identified as 61-year-old William Edward Mock, suffered serious injuries at about 3.50pm Thursday afternoon while working at the Blacksville No. 2 mine near the Pennsylvania-West Virginia border and later died.

“Initial indications are that he was struck by a rock along the track haulage,” Seay said, adding that no further details about the incident were available Friday.

“Consol Energy continues to work closely with federal and state mining officials to determine the cause of the incident.

“Our thoughts and prayers go out to the family of our deceased employee during this difficult time.”

A spokesman for the US Mine Safety and Health Administration told ILN later Friday that the miner was in the outby track area of the mine and it was not clear if the rock came from the roof or rib.

Federal investigators were onsite evaluating the scene but neither Consol nor MSHA could confirm Friday whether the issued 103k closure order was still in place.

MSHA records list Monongalia County, West Virginia as the mine location but Blacksville No. 2 actually stretches across the state line into Greene County, Pennsylvania.

Blacksville is a fairly sizeable longwall complex. Its 585 workers produced about 4.3 million tons of coal in 2011.

Mock was the second Consol miner to die on the job this year.

On January 11, utility/diesel tram operator Joe Saunders, 44, who had 20 months of mining experience, was struck in the head by a damaged fire valve manifold.

The manifold had been under pressure and Saunders was attempting to remove it. He was working at Consol Energy’s Buchanan operation in Virginia at the time.

The Blacksville death sparked concern across the industry as it occurred just days after longwall utilityman Julius Walker III, 28, was killed September 11 at Drummond Coal’s Shoal Creek mine in Alabama.

Walker, according to federal officials, was moving a spare longwall power center when he was pinned to the rib.

The pair of fatalities has also alarmed large industry union the United Mine Workers of America, which has called for increased safety vigilance from all US miners.

“The hearts and prayers of the UMWA and our entire membership are with the families of two miners killed on the job in recent days [and] we stand ready to assist those families in any way we can,” union president Cecil Roberts said.

He also noted the group’s international health and safety experts were working with investigators at both mines to help determine cause and prevent similar incidents in the future.

“While those investigations are underway, I urge every miner to be more vigilant than ever in identifying unsafe working conditions and staying away from them,” Roberts said.

“If it's not safe, don't do it.”