A second American has died after reaching the top of Mount Everest, the world’s tallest peak, amid dangerous overcrowding this climbing season.

Christopher John Kulish, 62, died suddenly Monday at a camp after climbing the mountain, USA Today reports.

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“He saw his last sunrise from the highest peak on Earth,” his brother, Mark Kulish, told the publication. “He passed away doing what he loved, after returning to the next camp below the peak.”

The cause of his death was unclear.

Don Cash, 55, of Utah also died during his descent from Everest last week.

The two Americans’ deaths are part of a growing list of climbers who have perished on or near Everest’s summit in 2019.

At least 11 climbers in total have died this season, according to Nepalese officials.

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Most of the deaths on Everest this year have been attributed to exhaustion and tiredness, exacerbated because a crowded route to and from the summit has led to delays.

At more than 29,000 feet above sea level, Mount Everest is the highest and most prominent mountain on earth based on measurement to sea level. Known as Asia’s Himalayas and the tallest mountain range in the world, Mount Everest spans across six countries: China, Nepal, India, Pakistan, Bhutan, and Afghanistan.

The air atop Everest has low oxygen levels that just being in the area near the summit, let alone climbing, can be lethal for those who cannot reach extra oxygen supplies fast enough.

The route, known as South Col, was pioneered by New Zealander Sir Edmund Hillary and Nepalese Sherpa Tenzing Norgay back in 1953.

About 5,000 people have scaled the Everest summit so far and about 300 have died on its slopes.

The short climbing season ends this month.