2 killed in mining accident in southwestern Colorado

Two workers were killed and 20 others were injured Sunday in a mining accident near the southwestern Colorado town of Ouray, officials said.

The Ouray County Sheriff's Office was called to the Revenue Virginius mine at about 7:20 a.m., county spokeswoman Marti Whitmore said. The two miners were underground and were confirmed dead Sunday afternoon.

The sheriff's office and the Colorado Department of Public Safety told CBS News that all the other workers were above ground and had been accounted for.

Rory Williams, project manager for Star Mining Operations, the operator of the Revenue-Virginius, told the Ouray Watch newspaper that accident was not related to a cave-in or mine collapse. He said apparently a "powder-smoke incident" and the release of chemicals injured the affected miners.

Whitmore said 20 people were taken to area hospitals, and all but two had been treated and released as of Sunday evening.

Officials from thee U.S. Mine Safety and Health Administration were at the accident site, which is about 270 miles southwest of Denver.