A Kentucky coal miner died Saturday in an accident at an underground mine, authorities said.

Lester Daugherty Jr., 48, suffered critical injuries while performing maintenance at a 16,000-foot deep River View mine in Waverly, the Kentucky Energy and Environment Cabinet said in a news release.

The state Division of Mine Safety sent investigators to the mine Saturday. Mining operations were shut down during the site inspection and the mine was closed for the investigation, authorities said.

Daugherty, of Sturgis, was a mechanic with 16 years of experience.

The Division of Mine Safety last inspected the mine in October, authorities said.

“My deepest sympathies go out to the Daugherty family,” Kentucky Energy and Environment Secretary Rebecca Goodman said. “We are investigating this accident and will to do everything that we can to understand how this happened and prevent such future loss of life among miners.”

(AP)