Colorado, South Maroon Bell. On 4 July Bruce Markel (18), Laurie Ashley and John Markel were separated from a group climbing the Bells. In crossing a snow couloir with Bruce in the lead, Bruce slipped and fell. He slid about 500 feet on snow and two rock patches and landed on a ledge, where he spent the night with his brother and Laurie attending him. In the morning John went down to get help. Several members of the main group, camped at Maroon Lake left at once, climbed up to Bruce and attended him until the Mountain Rescue group arrived with the doctor.
Source: Alfred Braun.
Analysis: Group should have been roped up and belayed and not separated from the main group.