Sherpas' headlamps in the Khumbu Icefall early in the morning. You can see more at: http://ngm.nationalgeographic.com/everest/blog. Cory Richards/National Geographic hide caption

itoggle caption Cory Richards/National Geographic

Unidentified mountaineers descend from the summit of Mount Everest over the weekend. Four climbers were killed trying to make it down the 29,035-foot summit. Pemba Dorje Sherpa/AFP/Getty Images hide caption

itoggle caption Pemba Dorje Sherpa/AFP/Getty Images