"We are sad to announce the death of Eberhard Schaaf, of Germany, at the south side of the summit of Mount Everest," Ang Tshering Sherpa of the Kathmandu-based Asian Trekking adventure agency said. The medical staff at the Himalayan Rescue Association believe the cause of death to be altitude sickness. Sherpa said South Korean Song Won-Bin, who had been missing since Saturday, died at "The Balcony," an area near the top of the peak. Tilak Pandey, a tourism ministry official at the Everest base camp, said separately that a Nepali-born Canadian woman named Shriya Shah had also been killed on Sunday. "Most of these deaths occur due to high altitude sickness," said Sherpa. Climbers spend their energy on the ascent and they are exhausted and fatigued on the descent. He added that a Chinese climber and a Nepali mountain guide were also missing.