OURAY, Colo. (November 18, 2013) Two miners who were killed in a mining accident Sunday in Colorado died of carbon monoxide poisoning, authorities say.
Twenty other workers were injured in the accident near the southwestern Colorado town of Ouray.
Officials said the source of the gas was under investigation.
They are looking at whether a small explosion in the mining process might have caused it.
Ouray County spokeswoman Marti Whitmore says 20 people were taken to area hospitals, and all but two were treated and released.
The Montrose Daily Press reported that 10 were taken to Montrose Memorial Hospital, where officials say they were treated for carbon monoxide exposure.
Rory Williams, the operations manager for Denver-based Star Mine LLC, says all of the men are required to wear personal respirators and the two who died had them.
He said that it doesn't appear to be an equipment malfunction.