(CNN) – After a deadly avalanche in 2014, and a major earthquake in Nepal last year, climbing season is open on Mount Everest.
More than 400 people have attempted the Everest climb this season, but last week proved to be a deadly one. Four people died in the span of just four days, and two others remain missing.
Crew member Phurba Sherpa fell to his death Thursday while working on a route near the summit. 36-year-old, Eric Arnold, of the Netherlands, died Friday night after a successful summit on Everest; a heart attack is suspected. On Saturday, an Australian woman died after she began experiencing altitude sickness; the 34-year-old was climbing alongside her husband. On Sunday, another climber died from altitude sickness.
Watch the video above to see Chad Myers explain why the world’s highest peak is so dangerous.