Two climbers who reached the summit of Mount Everest died on the way down from apparent altitude sickness, according to reports.

Eric Arnold, whose Twitter account said he was from Rotterdam, reached the summit on his fifth attempt. He was in a group of more than 40 climbers who reached the 29,035-foot summit on Friday, according to Reuters.

Employees of the Seven Summit Treks agency in Kathmandu told reporters that Arnold died at Camp IV and had been suffering from weakness and frost bite.

Hours later, another member of the expedition team, Australian climber Maria Strydom, died after showing signs of altitude sickness, the Associated Press reported.

Their deaths were the first confirmed this year on Everest. It was still undecided when and if their bodies would be brought down from the high altitude and it would depend on the team and family members.

The last tweet on his account was Friday and included a picture of him in full gear and an oxygen mask and, translated from Dutch, read “Mountaineer Eric Arnold reached top Mount Everest at fifth attempt.”

Strydom, a finance lecturer at Monash University’s business school in Melbourne, was attempting to climb the seven summits of the world with her husband, according to the AP. She had already climbed Denali in Alaska, Aconcagua in Argentina, Mount Ararat in Turkey and Kilamanjaro in Kenya.

Two of Arnold’s previous attempts to climb Mount Everest, in 2014 and 2015,  were cut short by deadly earthquakes, according to The Himalayan Times.

Arnold had told a local Dutch television station last year that climbing Mount Everest was a childhood dream, the Associated Press reported.

“I used to have a poster of Mount Everest above my bed,” he said.

via USA Today