Mount Everest is the highest mountain in the world in terms of altitude. Its summit is 29,029 feet above sea level. As the highest mountain in the world, Everest draws the largest number of people to take up the challenge of attempting to reach its peak. It is thus no surprise that it has also claimed the most lives so far. The ratio of deaths to summits for Everest is 1:33. Records suggest there have been just over 300 deaths on the mountain. The first recorded deaths on the mountain were seven porters who perished in an avalanche in the 1922 British Mount Everest Expedition. One of the most infamous tragedies on the mountain was the 1996 Mount Everest disaster on May 11, 1996, during which eight people died due to a blizzard while making summit attempts. On April 25, 2015, 19 people were killed in an avalanche at base camp following a 7.8 earthquake, which killed more than 9,000 people and injured more than 23,000 in Nepal.
The most common causes of death for climbers in Mount Everest are falls. The mountain is covered in ridges and soaring cliff faces and even short patches of bad weather can cause climbers to lose their bearings and slip or fall over the edge. A number of deaths on Everest have been the result of altitude sickness when humans struggle to adapt to the low oxygen levels at high altitudes, usually above about 10,000ft (3,000m). Altitude sickness can cause cerebral or pulmonary edema and hypoxia which are often fatal. Weather is also a key issue for all the climbers. The wind speed on Everest can climb above 100mph while temperature ranges from about 10oC to -25oC with frequent blizzards and white-outs.