Yosemite - A climbing guide who has helped people get to the top of Yosemite's El Capitan for 12 years says the big rock fall that killed at least one person and injured another was the biggest slide he's ever seen at the site.
John DeGrazio of YExplore Yosemite Adventures said on Thursday he had just reached the summit with a group of climbers when they saw large plumes of dust rising up the vertical wall of El Capitan.
DeGrazio says he's seen avalanches and rock falls on El Capitan in the past but that Wednesday's rock fall was "more significant than anything I've seen before".
He says climbers are aware of the risks of the sport and that granite erosion takes place on El Capitan and in the Sierra Nevada mountain range.
He says El Capitan climbers have been lucky that many rock slides have not killed people.
Meanwhile all areas in California's Yosemite Valley have once again opened.
At least 30 climbers were on the vertical wall of the 2 307m El Capitan when the huge rock hunk fell on Wednesday afternoon.