Three workers were injured when part of an underground coal mine collapsed in southern Montana on Wednesday morning.
The incident occurred at the Bull Mountain Mine, owned by Signal Peak Energy, near Roundup, about 50 miles north of Billings.
The workers were about a mile inside the mine when the area where they were extracting coal caved in for unknown reasons, according to Mike Stickler, a spokesman for Signal Peak Energy.
The injured workers were taken to a local hospital with non-life-threatening injuries, Stickler said. He did not provide details on their names or conditions.
The cause of the collapse is under investigation by the company and federal and state authorities. The mine has been temporarily shut down until it is deemed safe to resume operations.
The Bull Mountain Mine has a history of safety violations and accidents. In 2017, it was fined $230,000 by the federal Mine Safety and Health Administration for failing to prevent a fire that burned for five days. In 2019, two workers died in separate incidents at the mine.
The mine produces about 12 million tons of coal per year and employs about 250 people. It is one of the largest underground coal mines in the country.