Three climbers who completed a dangerous climb on the famed Mount Everest have been found dead on their descent down, while two others are reported to be missing. German doctor Eberhard Schaaf, 61, Nepal-born Canadian Shriya Shah, and South Korean Song Won-bin have been reported dead, while a Chinese national and his Nepalese Sherpa guide have yet to be found, officials said on Monday.

Schaaf did not scale the mighty mountain in order for his own personal glory. He took a team up to the summit in conjunction with Eco Everest Expedition to remove garbage and debris on Everest. On Saturday, he died on the Southeast Ridge Route.

Schaaf died at the South Summit of Sagarmatha due to altitude sickness, said Ang Tshering Sherpa, chief of the Asian Trekking company that organized the expedition as he referred to the traditional Nepali name for the mountain. The south summit is approximately 28,697 feet high, reported Reuters.

Sherpa said that the body of Schaaf was still lying on the mountain and the family as well as the German embassy had been informed of the tragedy.

If the family wants the body to be brought down we will try, but it is very difficult to do so from that altitude, Sherpa said.

The three climbers were believed to have suffered from exhaustion along with the altitude sickness. Officials were still conducting an investigation about the incident, reported the Associated Press.

There was a traffic jam on the mountain on Saturday, said Nepali mountaineering official Gyanendra Shrestha. Climbers were still heading to the summit as late as 2:30 p.m. which is quite dangerous.

Climbers are told that is very risky to attempt to reach the summit after 11 a.m. The area above the last camp is nicknamed the death zone. It is a steep and icy slope that is known for its extremely dangerous conditions and low oxygen levels.

With the traffic jam, climbers had a longer wait for their chance to go up the trail and spent too much time at higher altitude. Many of them are believed to be carrying a limited amount of oxygen, not anticipating the extra time spent, Shrestha said.

Sherpa also said that mountaineers often expend most of their energy during the ascent. Combined with the other deadly aspects of the mountain climbing, many climbers will not have enough energy for the return trip.

As a result, they become weak and suffer from altitude sickness, he said, reported CNN.

The climbing season usually begins in late March to the first week of June. The Nepalese government does not place any restrictions on how many climbers can attempt to climb the 29,035-foot mountain, the highest in the world. Tshering said that he believes  the government should impose some system of climbing so that there is not confusion which could cause traffic jams, reported the AP.

That is one reason that some climbers collapse after they reach summit. The other thing is when they put too much efforts, when they are very tired it also causes the altitude sickness, he said.

Approximately 3,700 people have scaled Mount Everest since 1953, when Sir Edmund Hillary of New Zealand and Sherpa Tenzing Norgay first reached the top. Reports indicate that at least 236 people have died on the slopes so far.