Krakauer's probably best known for his book "Into the Wild". I'd also recently read his book about Mormonism, "Under the Banner of Heaven". However I had no idea he had first-hand experience climbing Mt Everest, in which multiple people on his expedition team died.
This was a very tragic (and fairly short) book surrounding the extreme dangers of attempting to climb Everest. Climbers spend time acclimatizing at camps, but even at this point they've lost a lot of weight and developed other debilitating illnesses - and yet even through these struggles, they still go on to attempt the summit.
In the end the biggest danger is not knowing your own limits. It's not so hard to make it up the top of the mountain, but if you've used up all your energy, or you've spent most of the daylight hours trying to get up there, making it safely back down can become impossible.