Today in Field Test: On Everest, National Geographic writer Mark Jenkins recounts the recent days of drama that have transpired on Mount Everest. First there was an avalanche that tore across the route from Camp 1 to Camp 2. Just one person was caught in the slide, Nima Sherpa, who was thrown into a crevasse. He was rescued and is being treated for his injuries in Kathmandu. Then there was the scary evacuation of our own Cory Richards, who started having problems breathing and chest pain while descending from 23,000 feet on the mountain’s West Shoulder. Mark Jenkins explains exactly what happened on Cory’s difficult descent from the mountain.