Two workers were killed and twenty injured in an explosion at a mine in the US state of Colorado on Sunday. Twenty wounded miners were rescued and taken to a hospital while the bodies of the two deceased miners were pulled from the wreckage. The explosion and collapse occurred at the Revenue Virginius mine near Ouray town at about 7:30 am local time. Workers were stuck in the mine after the collapse and rescue efforts lasted until noon. The cause of the accident remains unknown.