California, Yosemite National Park. On 20 August Ronald Guest (21), Pierre Zetterberg (21), and Tom Rack (21) decided to climb a seemingly moderate wall between Murphy Dome and Fairview Dome near Tenaya Lake. There were no pre-established routes on this section of rock and they were merely going to do an easy 4th and 5th class ascent. The party had very little experience including Mr. Guest. As they climbed up, the difficulty went from 3rd to 4th to 5th class and consistently became more difficult. The party reached a 6 foot by 20 foot ledge 300 feet up from the base and Guest started a difficult 5th class lead. He climbed about 20 feet above the ledge and it became too difficult for him. He then placed a piton, clipped in an aid sling, and stood on it with the thought of passing the difficult part by the use of aid. The piton pulled out and he fell backwards onto his head and downwards to the ledge below him where he lost consciousness. Rack was able to apply artificial respiration and basic first aid while Zetterberg descended 3rd and 4th class ledges East of the route and summoned help. Mr. Guest had never used or practised aid climbing before.

Source: Steve Hickman, Yosemite National Park.

Analysis: There are many ways the accident could have been avoided. The party should have been wearing hard hats. When the route became apparently too difficult for them, which was obvious at the 6 foot by 20 foot ledge, they should have given up the climb. Extra caution should have been exercised realizing that the route they were on had never been climbed and that the group was made up of beginners. Protection should have been placed sooner than 20 feet off the ledge or the aid piton should have been placed for protection rather than aid. A greater knowledge of piton placement should have been known.