Nepalese mountaineer Apa Sherpa, who has scaled Mount Everest a record-breaking 21 times, is photographed while on the Great Himalaya Trail, one of the longest and highest trekking routes in the world, in the Nepalese Himalayas on January 22, 2012.
Three mountain climbers died and two others remain missing after attempting to descend from the summit of Mount Everest over the weekend. The deaths have caused many to question why so many are allowed to attempt to climb the world's tallest peak.
About 150 climbers tried to reach the peak of Everest as they rushed to use a brief window of good weather, according to the Associated Press.
Many had been waiting at a camp for several days for their chance to head to the summit. But the good weather brought extra climbers and created a traffic jam.
"Climbers had a longer wait for their chance to go up the trail and spent too much time at higher altitude. Many of them are believed to be carrying a limited amount of oxygen, not anticipating the extra time spent,'' Nepali mountaineering official Gyanendra Shrestha said.
A study published in the British Medical Journal in 2006 found that on average there had been one death for every 10 successful attempts to scale Mt Everest.
Ed Viesturs, the country's foremost high-altitude mountaineer, and the only American to reach the summits of all of the world's 14 8,000-meter peaks without supplemental oxygen.