US Mine Safety and Health Administration spokesperson Amy Louviere said that on Wednesday evening at Consol Energy’s Buchanan mine a miner was struck in the face and forehead by a damaged fire fighting valve under high pressure on a six-inch waterline.

“The valve had been isolated by shutting off cut-off valves both inby and outby the damaged valve [and] it is believed one of the valves was allowing water to leak through, which caused pressure to build up at the damaged valve,” she told ILN. “The valve blew off while the victim was in the process of removing it, striking him in the face/forehead area.”

While the identity of the worker was not disclosed, Louviere confirmed Friday afternoon that he was in critical but stable condition at a medical center.

Another unidentified miner received shoulder injuries after also being hit by the valve, and was in a stable but critical condition Friday. A third worker was treated as a precautionary measure and released.

Louviere said that an inspector was on-site at the mine when the accident occurred and issued a 103k order to temporarily suspend production. A federal investigation has commenced.

Officials also confirmed an accident at the Brody operation in Boone County, West Virginia, though the information available at press time was much more sketchy. An MSHA investigator was sent to the mine to check out the incident despite the operator not reporting the event.

“The accident is believed to have happened due to a piece of rock rolling out on the miner while he was bolting,” Louviere said.

The condition of that miner was unknown Friday afternoon.