Ten years after "Into Thin Air," people are still dying on their way to the top of Mount Everest, and we are still avidly reading about them.

"Dark Summit: The True Story of Everest's Most Controversial Season," by Nick Heil (Holt, 271 pages, $26), is the story of the 2006 season, the deadliest since the 1996 season chronicled by Jon Krakauer.

In those 10 years, Heil notes, mountain climbing has continued to become less of a calling and more of a business. Russell Brice's Himalayan Experience, for example, runs fresh ropes to the summit every spring and charges all other expeditions $100 a head for the service. They schlep tents and beer and strobe lights halfway up the mountain for post-summit parties; they hire sturdy, dependable Sherpa guides to accompany climbers, sometimes at a ratio of 1-1.

Brice stays at base camp, watching the expedition through high-powered binoculars, barking orders into satellite phones to turn around when people look wobbly, or when weather worsens.

But technology and organization can only do so much.

You still have to deal with the weather. You still have to deal with the lack of oxygen. And you still have to deal with the ever-increasing number of people who know almost nothing about climbing, but who somehow believe they have a God-given right to the top of the mountain.

Spring of 2006 saw a ragtag band of explorers: a double amputee. An overweight, almost blind German. A California motorcyclist who had nearly died in a crash and was now held together with metal screws and plates. None of them was a mountaineer.

As Heil says, "Those who took the stage were no longer professional adventurers and elite alpinists but, rather, an increasingly broad core sample of the world's middle class."

The weather that spring was mild, by Everest standards. Bitter cold, but with more clear days than usual. Still, the death toll was high.

One of the first to die was David Sharp, who lay in the snow for hours as dozens of hikers trudged past on their way to the summit. The next week, a steady stream of hikers trudged past another collapsed climber, who also was left for dead. (He survived.)

Heil's book explores the ethical question of risk. When you're hiking to the top of Everest, and you have planned your trip meticulously, you have paid $40,000, you have just feet to go before you summit, and you will likely never be there again, should you forgo the summit and help a dying man? Or is it every man for himself?

Heil doesn't answer this outright. But his book makes very clear that modern mountain climbing has become less about the mountain, even as it has become all about the climber.

Laurie Hertzel • 612-673-7302