The Everest climbing season recorded the first casualties as two climbers, a Swiss and an American, perished during descent, according to the expedition organiser.

Abdul Waraich of Switzerland, and Puwei Liu of USA, breathed their last on Wednesday night.

Abdul summited the peak but collapsed at the South Summit during his descent. The other, Puwei Liu, reached Hillary Step before turning back. He was helped back to Camp IV at the South Col where he ultimately passed away, according to Chhang Dawa Sherpa, Director at Seven Summit Treks.

"Abdul successfully reached the summit but began experiencing issues during his descent. He was exhausted," Sherpa said. "We sent two additional Sherpas with oxygen and foods, unfortunately they couldn't save him."

On the other hand, Puwei Liu took his last breath at Camp IV (7900m -S col). While descending from Hillary Step (the max height he gained), he began suffering from Snow Blindness and exhaustion. Consequently, one more hour was added to the stipulated descent time but with the help of extra oxygen supply and additional Sherpa support, he safely reached the South Col. "However, he suddenly passed away late on Wednesday evening."

Seven summit Treks will recover their bodies at the earliest once weather permits, says Sherpa