Four climbers have died while coming down from the summit of Mount Everest.
It's sparked questions over whether too many people are on the mountain at the same time.
More than 100 people tried to reach the summit on Friday and Saturday, causing delays on the route.
Scaling the world's highest peak is really tough. It's thought the climbers died from exhaustion and altitude sickness.
The four who died were from China, South Korea, Germany and Canada.
Dangers up high
At high altitude, there is less oxygen so your body has to work much harder to breathe.
There are also other dangers, such as bad weather, frostbite and hypothermia - that's when your body drops to a critically low temperature.
Timing is really important. The worry is that if there are too many climbers, then any delays could quickly turn into a matter of life and death.
Famous British mountaineer Sir Chris Bonington led the first ever ascent of Everest's south-west face in 1975.
He thinks there should be a limit on how many people are climbing at once.
But 22-year-old climber Matthew Dieumegard-Thornton, who got to the top on Saturday, said numbers were manageable.
He called for respect between climbers: "As long as the climbers are courteous of other climbers on the mountain, everyone can work well."
The mountain's worst ever climbing season was in 1996, when 15 climbers died - eight of them in one day.