Australian engineer Jason Kennison was the 10th climber to die on Mount Everest this spring in one of the deadliest climbing seasons in recent history.
The 40-year-old South Australian man died of altitude sickness, where the brain swells from lack of oxygen, according to tour operator Asian Trekking.
The condition is among many causes that claim the lives of climbers on the world's highest peak each year.
And this year has already been twice as deadly as usual.
How many people have died on Mount Everest?
At least 322 people have died on Mount Everest in total.
That's based on records kept by The Himalayan Database, dating back to 1922.
It's an average of about 4.4 fatalities each year there are records of people climbing.
The database names eight Australian mountaineers who have died, excluding Mr Kennison.
About a fifth of fatalities occur in the autumn climbing season, with the majority occurring in spring, when conditions are largely considered the best.
The challenge has grown in popularity over time and if you're looking at data since the turn of the century, the average of annual fatalities has also grown to 6.4.
Why have more people died this climbing season?
The record number of people allowed to climb to the summit this year could be contributing to the higher-than-average death toll.
Nepal issued 478 Everest climbing permits this season, the highest ever, and if you include Sherpa guides the number of people climbing the mountain this season is even higher.
The previous Everest permit record was 408 for the 2021 season.
Mountaineer and summit coach Alan Arnette, who has climbed Everest four times and reached the summit in 2011, described this season as a "chaotic mess".
He wrote in Outside Magazine that this year's fatalities included four Sherpas and six foreign climbers.
An incident on April 12 killed three Sherpa guides when an ice tower collapsed and buried them.
"The seven other fatalities were all due to sickness, cold, or exhaustion," Mr Arnette wrote this week.
"At time of publishing, several climbers are missing on the mountain, and the death toll could rise in the coming days."
The rate of climbers dying each year hasn't actually increased
The death rate per 100 climbers has remained relatively steady over the years, bar a few tragic and quiet years on the mountain.
A study published by the University of Washington and the University of California Davis in 2020 found the death rate for climbers had hovered unchanged at around 1 per cent since 1990.
Researchers found the success rate of summitting Mount Everest had actually doubled in the past three decades, even though an increase in climbers had crowded the narrow route through the dangerous “death zone” near the summit.
And success at the summit doesn't always mean people return home safely.
Professional mountain guide Allan Cohrs does have concerns for the future on the mountain, saying an increase in climbers creates risks.
He said large teams often head for the summit at the same time, when a clear weather window has been identified.
"This creates a huge bottleneck, with climbers standing idle at seriously high altitudes, which increases the chances of frostbite, fatigue and unnecessary exposure to the elements whilst in the death zone," Mr Cohrs said.
He believes the rise in permits has also created an increase in inexperienced climbers on the mountain.
What are the most common causes of death?
Avalanches and falls have taken the most lives on the mountain.
Acute Mountain Sickness (AMS), exhaustion, non-AMS illnesses, and exposure to the elements have also been cited frequently as causes of deaths.
Mr Cohrs lost a close friend and experienced climbing Sherpa Ang Kaji in an avalanche on the mountain in 2014 — a reminder that the death toll represents real individuals who have left behind loved ones.
"We had shared many expeditions together including Everest and Cho Oyu … and he was an incredible man," he said.
"There are sad stories up there, but everyone knows the risk."
Mr Cohrs said each death on the mountain impacts the climbing community.
"The recent death of Australian climber Jason Kennison was such a sad loss, especially considering the incredible determination and strength he obviously had, particularly after being told he would never walk again, to then go on and reach the summit of Mt Everest," he said.
"My heart goes out to his family and friends."
When climbing becomes an addiction
Climbing high altitude peaks gives people a purpose and the feeling can become addictive, according to Mr Cohrs.
The Australian owner of Everest One reached the summit in May 2011 and said it was one of the most "satisfying, spiritual and ultimate challenges".
"It is difficult to describe the incredible feeling of elation and personal satisfaction when, after months of training, sacrifice and self-discipline, you finally reach the summit," he said.
Mr Cohrs has climbed more than 25 peaks above 6000m in the Himalayas, and said each climb felt special.
"Many people believe that climbing is a selfish pursuit, where people unnecessarily put themselves at risk," he said.
"I understand how people can have this perception, but we are all motivated differently, and if you respect the mountain, tread carefully and accept that the summit is not guaranteed, you can certainly improve your chances."
What can climbers do to reduce their risk of death?
Preparation, training and gradually gaining experience on lower peaks is the key to success, according to Mr Cohrs.
"I do not agree with taking on a climb like Mt Everest without any prior experience, as this is dangerous for not only the individual climber, but also the Sherpa and Western guides, and other climbers," he said.
"It is seriously challenging, takes great commitment, but it is no place for the faint-hearted or inexperienced."
Mr Cohrs said while the mountain can be unpredictable and some factors cannot be controlled, taking steps towards governing the level of experience required for a permit could help.
"I believe that people should climb for the love of climbing, and Mount Everest should not be a bucket-list pursuit," he said.
