There was menace even in K2's perfect weather at the start of the latest tragic climb, according to 23-year-old Californian Nick Rice, who was forced by frostbite to abandon his own effort to reach the top, reports CBS News correspondent Richard Roth.
"There was perfect visibility, actually almost too perfect, like something's going to go wrong," Rice said.
As a group of climbers approached the five-mile-high peak after midnight Friday, it did.
Along two paths, the climbers had begun their final push in early-morning darkness when a Serbian fell to his death and a Pakistani porter died trying to recover the body.
The others moved on to the summit, but time had cost them oxygen and energy, and their descent turned deadly.
An ice ledge suddenly sheared off the mountain face, cutting guide ropes, killing at least four climbers and stranding the rest in a place known as "the death zone."
The thin air was 40 below zero, and climbing down K2, it's said, is even harder than climbing up.
"By the time somebody gets to the summit of K2, they're exhausted," Rice said. "So coming down you're a bit clumsy. It's not a matter of technical skill anymore. It's a matter of being able to battle the deteriorating mindset that you've got-being able to have the stamina to survive."
Two Dutchmen did come out alive. And today, a Pakistani helicopter carried out the last survivor: an Italian climber who staggered down K2, weak and badly frostbitten from trying to help save others in the group. Instinct, he says, makes you want to do that.
Climbers call it the world's deadliest mountain. For every three who make it to the top, one dies trying.
On K2's makeshift shrine, 11 new names have just been added.