A helicopter dangling alone rescue worker by a thread searched for survivors on the East Buttress of El Capitan.
Fresh scars on the wall show where chunks of granite started peeling off Wednesday morning.
Phone interview with Peter Zabrok on the El Capitan Waterfall route
From his perch 2,000 feet higher on the wall, Canadian climber Peter Zabrok called us to describe what he had seen.
"It was the size of an apartment building. I saw it, 100 foot by 100 foot pure white El Capitan Granite, from 2,000 feet up," said Zabrok.
The rockslide came crashing down on the waterfall route-- popular route Zabrok had just crossed one day ago.
"At the base, I saw I think two or three people. I do not know what happened to them. I pray that they are safe."
Park officials confirmed his worst fears Wednesday afternoon. One climber died, but another survived and was airlifted to safety.
"It was done at tremendous peril to the rescuers because there were three subsequent rock falls that were all nearly as big and would have killed anybody at the base."
The rockslide comes during the peak of the climbing season--a time when skilled and experienced climbers converge at El Capitan every year.
"This is my 58th different El Cap route that I've climbed. I've never seen anything like this; if we had moved at my usual lazy pace it would have clobbered us."
At dawn, Zabrok will resume more cautiously than before and so will the search for more fallen climbers.