Eric Nourse of Greeley, Colo., and David Reinhart of Lake Oswego, Ore., were killed Friday while tackling the challenging route, up the face of a glacier -- a bald sheet of ice with very little snow for traction, The Denver Post said.
After leaving the mountain's high camp at 19,200 feet on their way to the summit at night, Reinhart began suffering from motion sickness. Nourse, and his twin brother Greg who completed the trio, continued to the top in hopes of finding the easier route back down the mountain.
Fellow climbers eventually gave them the route down and Greg Nourse called his wife from a satellite telephone to send for help for Reinhart.
After returning to the 19,200-foot encampment, emergency workers told Eric Nourse his blood oxygen level was dangerously low. While pausing to rest before climbing back down the mountain, his heart stopped and efforts to revive him were unsuccessful, his brother said.
Reinhart's body was recovered later that day.