(CNN) An American mountaineer died Wednesday while descending from the summit of Mount Everest, according to the Nepalese company leading the expedition.

Donald Lynn Cash, 55 of Sandy, Utah, fainted due to high altitude sickness after reaching Everest's summit, according to Pioneer Adventure Pvt. The expedition company said its guides tried to give Cash aid while bringing him down the mountain

"Our supporting Sherpa Guides did immediate massage, CPR and raised his oxygen pressure to keep him alive," the company said in a news release. "In that situation, our Sherpa Guides tried to rescue and drag him down towards Camp 4 as quick as they could."

Cash had collapsed near a portion of the trail called the "Hillary Step," an elevation of approximately 8,770 meters, according to Pioneer Adventure.

"Despite their best efforts in providing the best guidance, sufficient oxygen supplies and medical support they could not save his life," the company said.

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