A second American died after reaching the summit of Mount Everest as the world’s tallest peak faces a growing death toll amid dangerous overcrowding this climbing season.

Christopher Kulish, 62, a Boulder, Colorado, attorney, died Monday at a camp after summiting the mountain, his family said.

After he stood atop Everest, Kulish joined the elusive “Seven Summit Club,” earned after ascending the tallest mountain on each of the seven continents.

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

‘Every minute counts’: Another climber dies on Everest as world’s tallest peak overcrowds

Don Cash, 55, of Utah, also achieved a lifelong dream of reaching the top of the seven tallest peaks on each continent, but like Kulish, died in 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. According to Reuters’ count, at least nine climbers have died this season, though some news outlets place the number at 11.

Most of the deaths have occurred after climbers spent extended time in the mountain’s “death zone.”

At 29,035 feet, the air atop Everest has such low oxygen levels that just being in the area near the summit, let alone climbing, proves lethal for those who cannot reach extra oxygen supplies fast enough.

Utah climber dies: He climbed the tallest mountain on each continent, then died as he descended Mount Everest

Nearly 400 climbers and just as many sherpas were permitted to scale Everest this season from Nepal’s side of the mountain.  Coupled with poor weather closing the window to summit the mountain to a few select days, Everest has seen massive queues just below its peak where climbers must wait in line to reach the top.

“Once you get above about 25,000 feet, your body just can’t metabolize the oxygen,” Grayson Schaffer, editor of Outside magazine, told NPR. “Your muscles start to break down. You start to have fluid that builds up around your lungs and your brain. Your brain starts to swell. You start to lose cognition. Your decision making starts to become slow. And you start to make bad decisions.”

Nepal’s tourism department has downplayed the effect the growing number of climbers has had on this year’s death toll.

While people die every year on the mountain, some say this year’s crowds have been particularly concerning.

Speaking with the Washington Post, Nirmal Purja, who has  reached the top of Everest four times, said: “I’ve seen traffic, but not this crazy.”

Contributing: The Associated Press.

Follow USA TODAY’s Ryan Miller on Twitter: @RyanW_Miller