Half Dome and Yosemite Valley in a view from Glacier Point at Yosemite National Park, Calif. (AP Photo/Tracie Cone, File) Clinging for life to a cold steel cable, high on a nearly vertical rock face in the Sierra Nevada, the soles of my hiking shoes simply could not find traction. Again and again, as my forearms trembled and my fingers ached, my feet slipped on the mercilessly smooth granite.

A fall from that height — on the climbing cables that mark the final 400-foot ascent to the summit of Yosemite’s Half Dome — could easily be fatal. So I clenched my fists tighter and inched toward the top. The only relief came from irregularly spaced wooden slats drilled into the rock that provided desperately needed footholds.

I was right to be nervous. The wide stretches between some of those wooden slats, particularly on the steepest parts of the final ascent, are notoriously treacherous. Last month, while descending the same stretch in a sudden rainstorm, 20-year-old Grace Rohloff slipped on the slick rock and she lost her grip on the cables.

In a flash, she slid past her father’s outstretched hand, and he watched helplessly as she plummeted hundreds of feet to her death. She wasn’t the first: At least 10 others have died in falls from that stretch, usually when the rock is wet. Grace Rohloff was an experienced hiker who celebrated reaching the Half Dome summit with her dad just moments before the tragic accident.

https://t.co/60VT8Uunj6 In a phone interview last week from .