Mountaineer Chizuko Kono died of exhaustion last week while climbing in the Himalayas, while a Spanish climber was killed by an avalanche on the same mountain, Kono's Sherpa and Nepalese officials said Tuesday.

Dawa Sherpa, who was with the 66-year-old Kono until her death, said she died last Thursday night at an altitude of 7,700 meters on Mount Dhaulagiri, the world's seventh-highest peak, even though he tried to give her a high concentration of oxygen.

"It was the biggest tragedy of my life," he said.