Through the afternoon, the rescue helicopters shuttled back to the windswept rocky plateau where the southern base camp was located at the foot of Mount Everest.
Among the hundreds of mountaineers gathered there, Canadian climbers Joe Raftis and Shehbaz Butt saw the helicopters repeatedly return, each hoisting a long line harnessed to the body of a Nepalese guide.
Attached by the neck and hips, the limp bodies "looked like rag dolls," Mr. Raftis recalled.
It was a week ago, after an ice avalanche killed 16 guides near the treacherous Khumbu Icefall as they were preparing the route for foreign climbers.
The tragedy was the largest one-day death toll in Everest history, exposing the precarious working conditions of the Sherpas, several of whom threatened afterward to strike to obtain better compensations.
Several expeditions have cancelled their climbs over safety concerns and rising tensions among the Sherpas.
"This has been a very tragic and moving experience … I feel like I left a little of myself there," Dr. Butt said Thursday in an interview he and M. Raftis gave from Nepal.
An anesthesiologist at Markham Stouffville Hospital, Dr. Butt, 42, helped treat some of those injured in the avalanche.
He and Mr. Raftis, 53, owner of the Toronto store Europe Bound Travel Outfitters, have been trying to climb the highest mountain in each of the seven continents. Everest was to be their fifth peak. Dr. Butt was also using the trip to raise money for his hospital.
More than 300 foreigners had permits from the Nepalese government to scale Everest this year.
The two men were part of an expedition run by High Altitude Dream, a Nepalese guiding company.
Until last week, the biggest challenge for the two had been the headaches that came with the thinner mountain air, since the base camp is at an altitude of 5,364 metres.
Friday was supposed to be a rest day before a training trek in the Khumbu Icefall.
The area is a crevassed, constantly moving field of massive glacier blocks that Sherpas cross repeatedly to mark the route with ropes and ladders and ferry supplies farther up the mountain.
Around 6:50 a.m., Mr. Raftis was sleeping when he heard an avalanche. He did not pay attention at first because each day at base camp is often punctuated by the sounds of avalanches or rock slides far away.
But within minutes, the commotion outside his tent made him realize something was wrong.
As news came back that a massive glacier had detached from the mountain side and buried a group of guides, the Sherpas still at the base scrambled to put on their harnesses and crampons and headed out to help their colleagues.
Most of the foreigners were not yet acclimatized enough to venture farther away.
Within hours, helicopters began hoisting back the dead.
"It was quite an emotional scene, those dead bodies coming down," Mr. Raftis said.
Dr. Butt and six other climbers who were also physicians looked after the more seriously injured.
He helped stabilize a man who arrived unconscious, with head trauma, to be airlifted to a Kathmandu hospital, and treated a guide for a broken leg and another with broken ribs and kidney injuries.
The Canadians' guide, Pasang Dawa Sherpa, was supposed to be on the mountain that day but had decided to take a rest.
Two days after the tragedy, more than 300 Sherpas held a meeting where grief and anger boiled over. They made a list of demands for better financial compensation and a larger share of the royalties collected by the Nepalese government. Some threatened to walk out.
"We could feel the tension," Mr. Raftis said.
Other foreigners reported that they witnessed similar acrimony.
"Emotions are running wild and demands are being made to the government to share the wealth with the Sherpa people," Everest guide Tim Rippel of Nelson, B.C., wrote on his blog.
"The ambience at base camp is becoming increasingly tense. There is a small group of renegade Sherpa from peripheral teams who are threatening violence towards anyone who chooses to stay and climb," Monica Piris, team doctor for the Alpenglow expedition, wrote on her team's website.
By Thursday, six groups had cancelled their climbs. Mr. Raftis and Dr. Butt were among those departing without having scaled Everest.
Both want to try again but said they will consult their families first.
Dr. Butt has four young children. A father of three, Mr. Raftis already had a close brush last year when he finished the Boston Marathon an hour before a terrorist bomb went off. This year, the avalanche fell the day before he was to head out to the Khumbu Icefall.
The two also pondered the mixed legacy of foreign climbers visiting Nepal that enabled Nepalese mountain guides to earn more than school teachers, but consigned them to arduous, dangerous labour.
"They are the unsung heroes behind the scene," Dr. Butt said. "Mountaineering has given the region an economic boost, but at the same time, it has come at a great cost."