American climber falls to death on Mount Everest

An American climber died on Mount Everest while trying to scale the world's highest peak with his brother, a Nepalese mountaineering official said Tuesday.

Michael O'Brien, 39, of Seattle, Washington, slipped and fell into a crevasse as he and his brother Chris, 32, were returning to their base camp on Sunday. They were crossing the Khumbu Icefall, a dreaded section of the route that has claimed the lives of many climbers, said Rajendra Pandey at the mountaineering department in Katmandu, Nepal's capital.

Climbers say the Khumbu Icefall looks like a mass of huge ice cubes spread across the mountain. Freezing temperatures at night and the warm sun during the day make the ice unstable and unpredictable. Climbers use lightweight aluminum ladders tied together by ropes as bridges to cross over crevasses in the ice that can be as deep as 30 meters (100 feet).

According to their Web site, the O'Briens were attempting to be the first American brothers to summit Mount Everest together.

Their father, Dr. David O'Brien, said he learned about the accident from his surviving son, the Seattle Times reported. "Christopher obviously was pretty shaken up," he said. "They were inseparable."

The O'Briens wanted to raise money for the Hereditary Disease Foundation, which supports efforts to find cures for diseases such as Huntington's, Alzheimer's, and Parkinson's.

The Seattle Times reported that Michael O'Brien lost his mother to Huntington's disease in 1996 and his sister in 1999 and knew he had a 50-50 chance of getting it, too.

O'Brien is the second casualty on 8,850-meter-high (29,035-foot-high) Everest this year. Last week, Canadian climber Sean Egan, 63, died on the mountain after an apparent heart attack.

Egan, a University of Ottawa professor who studied mental and physical training for climbers, had been suffering from a respiratory infection and was heading down the mountain for medical assistance but collapsed and died before receiving help.

Since New Zealander Edmund Hillary and Sherpa Tenzing Norgay first conquered Everest on May 29, 1953, more than 1,400 climbers have scaled the mountain. About 180 people have died on its unpredictable slopes.

BINAJ GURUBACHARYA, Associated Press Writer

On the photo: The Khumbu Icefall