Federal mine safety inspectors on Monday were trying to determine the cause of an accident that killed two miners and injured 20 others near the mountain town of Ouray in southwestern Colorado.
According to the Mine Safety and Health Administration, a foreman and a miner at the Revenue Virginius Mine, which conducts underground gold and silver mining, were overcome by gas in an area where an explosive had been detonated.
The fallen miners, identified as Nick Cappanno, 34, of Montrose, and Rick Williams, 59, of Durango, died of carbon monoxide poisoning, officials said.
Mine rescue teams searching for the men detected fatal levels of the gas, and 20 miners were taken to hospitals, said Amy Louviere, a spokeswoman for the mine safety agency. All have been released.
The mine, owned by Star Mine Operations of Denver, has been cited for more than two dozen federal safety violations since the company began operating it in 2011.
Many of the violations involved the misuse of electrical equipment and machinery, or a failure to follow safety precautions, federal mine safety records show.
In the most recent incident, on Oct. 22, federal inspectors cited the company for failing to secure gas cylinders safely and for using defective equipment.
According to the mine safety agency, the rate of workdays lost to nonfatal accidents at the mine was more than double the national average for each of the past two years.
Rory Williams, the mine’s manager, who is not related...