Wyoming, Grand Tetons, Summetry Spire. At 2100 on 13 August Joe Hogsed (19) and Betty Lu (21) were climbing the Durrance Ridge. They had completed the ridge and were scrambling the last 250 feet to the summit. The weather was bad; rain and thunderstorms were occurring. Mr. Hogsed felt that the best course was to rappel off to the west down a sheer face, rather than going to the summit and down the regular descent. He fixed a rappel, but forgot to knot the end of the rope. He tied a prussik knot to the rope, rappelled to the end, but did not find a ledge. The prussik caught on one end, and his weight pulled the rope through his anchor. Miss Lu saw this happen and tried to grab the rope, but it burned through her hands in a second. Then she heard a crash a few seconds later. She waited on a ledge, calling for help till midnight. A party heard her cries and notified a ranger.
Source: Ralph Tingey, GTNP.
Analysis: Better knowledge of the mountain itself would have helped the party to a safe descent route. More experience would have had Mr. Hogsed tie a knot in the end of his rappel rope. A middle mark on the rope may have prevented his prussik knot from coming off one end of the rope.