There are typically only a few days per year with the right conditions to summit Mount Everest.
Business Insider reports many parts of the mountain only allow one person to climb at a time, creating a bottleneck.
The death of at least two climbers has been blamed on large crowds that have left people queuing in the mountain's "death zone."
The death zone is an area more than 26,000 feet above sea level where oxygen is so limited that the body's cells start to die.