Introduction
In the wee hours of the morning of August 1, 2008, some thirty climbers from ten different expeditions set out from their high camps on the Abruzzi Ridge of K2. At 28,251 feet the world's second- tallest mountain, K2, thrusts skyward out of the Karakoram Range of northern Pakistan. After weeks of sitting out bad weather, the mountaineers were poised to go for the summit on a clear and windless day. During the endless storms, morale at base camp had reached rock bottom, and some climbers had thrown in the towel and gone home. But now everybody still on the mountain was jazzed. As they emerged from their cramped tents to clip on crampons and hoist packs, the climbers were riding a manic high. Sometime that day, they thought, they would claim one of the most elusive and glorious prizes in mountaineering. For most of these men and women, K2 was the goal of a lifetime.

Chapter 1: T H E M OT I VATOR
Although the various teams were operating independently, they had tried to cobble together a common logistical plan that would help everyone get to the top. The crucial feature of that plan was the fixing of thin nylon ropes-- to be used on the way up, in effect, as handrails, and on the way down as lines that could be easily rappelled. Those fixed ropes were intended to ensure the climbers' passage through the Bottleneck, a steep and dangerous couloir of snow and ice that rises from an altitude of 26,400 feet.

The Bottleneck and the sketchy leftward traverse at the top of it form the "crux" of the Abruzzi Ridge. Although climbing the Bottleneck is only moderately difficult, what makes that high gauntlet so nerve- racking is a gigantic serac-- a cliff of solid ice-- that looms above it. Weighing many tons, poised at a vertical and, in places, an overhanging angle, the serac looks as though it is barely attached to the mountain. Yet in the sixtynine years since mountaineers first came to grips with this formidable obstacle, the serac had proved remarkably stable. It seemed, indeed, to be a permanent feature of K2's summit pyramid.

Thirty climbers crawling up the same route on the same day would have been business as usual on Mount Everest. On K2--a far more serious mountain, and one that has seen far fewer attempts-- such a crowd was unprecedented. Still, as they approached the Bottleneck, thanks to the perfect weather for which they had waited so long, the climbers were awash in optimism. The summit was within their grasp.

And then things started to go subtly wrong. Small mistakes were made. Miscommunications, fueled by the many different languages the climbers spoke, flared into angry words. The slower climbers began to block the way for those who were capable of moving faster. Yet the single event that turned an awkward day into a catastrophe was nobody's fault.

Within the next thirty- six hours, eleven of those mountaineers would die high on the Abruzzi Ridge. The disaster that unfolded on August 1 would end up as the worst single- event tragedy in the mountain's history, and the second worst in the long chronicle of mountaineering in the Himalaya and the Karakoram.

And nobody saw it coming.
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Almost sixteen years earlier, on August 16, 1992, with my partners Scott Fischer and Charley Mace, I had left our high camp in the predawn darkness and started trudging up toward the Bottleneck. On that day, I, too, had been full of bursting hope, tempered by the wary alertness that is the obligatory state of mind for any alpinist who wants to stay alive in the great ranges. I had previously climbed Everest and Kangchenjunga, the first- and third- highest peaks in the world, but I knew that K2...