WADE GOODWYN, HOST:

This is WEEKEND EDITION, from NPR News. I'm Wade Goodwyn. Nepalese officials say that an avalanche killed at least 12 mountain Sherpas on Mount Everest. The avalanche struck yesterday at about 6:45 in the morning local time at 20,000 feet, just above the Everest base camp. The Sherpas were preparing the climbing route ahead of the busy summer climbing season when the accident happened.

Conrad Anker is a seasoned climber and was part of the team that discovered the body of George Mallory in 1999, a British climber who died on his ascent of Everest in 1924. Conrad Anker joins us from Bozeman, Mont. Conrad, thanks for being with us.

CONRAD ANKER: Thank you for the invitation.

GOODWYN: The news from Everest can sometimes be terrible. You've climbed the mountain. Can you explain to us what happened?

ANKER: The climbers were on the south side, which is the route that originates in Nepal and goes up the Khumbu Glacier to the South Pole, then on to the summit. They key point on this is climbing up through the Khumbu Icefall, and this is a stretch of glaciers that tumbles over a drop. And it's sort of like a river rapids, if you can imagine, but ice. And so there's blocks, and there's a lot of objective hazards. And it's the most dangerous part on the route as you go towards the summit.

And in this case, we had Sherpas that were carrying loads through the icefall. And one of the hanging glaciers to the east of the climbing route, hanging off the west shoulder of Everest, released; and then that avalanche of ice blocks is what took the lives of the Sherpas.

GOODWYN: All of the victims were Sherpas, a distinct ethnic group. We've been conditioned to think about Sherpas as the group who are perhaps the least likely to die on the mountain. What happened here? Why only Sherpas being killed?

ANKER: In this instance, they were carrying loads to get up to support the Western climbers that will then make their summit bid. So the Sherpas will probably travel through the icefall four times as often as a Western client will. So a Western client might make one to three trips through the icefall for their summit bid. But for the Sherpas, they're going to be carrying maybe four times as many. So they're carrying up the gear and the equipment for their customers. That's kind of their job. And on any given day, there's going to be quite a large amount of Sherpas that are going to be at risk because they're climbing in the icefall.

GOODWYN: Entire communities of Sherpas depend on the mountaineering industry for their livelihoods. Is the money pressuring them to take too many risks?

ANKER: A good question. There - I mean, obviously, I climb mountains because it's my avocation. I love it. It's what I want to do with my time off. And I'm willing to take the risk, and everything like that. For the Sherpa, it's a vocation. They are being paid to carry loads up on the mountain and to guide Western groups up there - and the same thing as a guide would work in the mountains here. So there are some - and it's a market economy, when Nepal is a very poor, landlocked nation in a geopolitical vise between China to the north and India to the south.

So mountaineering is really the engine that drives their economy, particularly the tourism economy. So when these Sherpas have the opportunity to earn the income that they do, it is - I can't fault them for wanting to go do it because it's good wages, relative to the average in Nepal. And it's fun. It's exciting work. But as we all know, it's very dangerous.

GOODWYN: Conrad Anker is the leader of the North Face climbing team. Conrad, thanks for being with us.

ANKER: Thank you for the invitation. Transcript provided by NPR, Copyright NPR.