Scaling K-2, the world's second-highest mountain and perhaps the deadliest to climb, requires the willingness to die in the process.

"People who take on a mountain like K-2 have to be prepared to write themselves off, and I'm not," said Will Cross, a 41-year-old Highland Park climber with Type 1 diabetes who has climbed the highest peaks on seven continents, including Mount Everest -- but not K-2.

It's been described as "Savage Mountain" and "Suicide Mountain."

"Call me old-fashioned," Mr. Cross said. "You have to be very comfortable with the chance you won't come back. But that's part of the allure, the risk."

K-2 revealed its treachery Saturday.

Eleven climbers were feared dead after ice sheared off its summit and crashed down the slopes, sweeping away fixed ropes and climbers. Others may have died trying to descend after the avalanche.

At 28,251 feet, K-2, in the Karakoram mountain range in northern Pakistan, is precipitous, especially approaching the summit. The entire mountain features rocky, icy slopes and volatile weather conditions. The tragedy occurred in the Bottleneck section of the mountain at 26,000 feet, also known as the "Death Zone."

Seventy-seven have died on the mountain compared with about 300 who've reached the summit since Italians first did it in 1954, a death-to-summit ratio of more than 25 percent.

Chris Warner of Earth Treks Inc. in Columbia, Md., who climbed K-2 last year, said most of the ascent and descent require "technical" climbing, or the use of hands and feet to stay on the slope.

Mount Everest, the world's tallest peak at 29,029 feet, has had 4,000 people reach the summit, with a death-to-summit ratio of only 1.8 percent. All but 200 feet of Everest can be scaled without technical climbing, Mr. Warner said.

For those reasons, Mr. Cross, a father of six, said K-2 offers the ultimate challenge because "it's high, hard, requires every skill and is more difficult than you can imagine."

"The reason I've chosen not to climb it is because I have a family," he said.

Mr. Warner, who has undertaken 150 expeditions, teaches climbing and guides climbing expeditions, said he knows of no one in Western Pennsylvania who ever attempted to climb K-2, and for good reason.

"They're too smart out there," he said of Western Pennsylvania climbers. "Or they're mama's boys, and their mamas won't let them climb it."

Mr. Warner, whose mother tried to persuade him not to climb K-2, reached the summit on his third try. As with climbing a ladder, he said going up is easier than the descent, when most deaths occur on K-2.

Everestnews.com reported that three Korean, two Nepalese, two Pakistanis and a climber each from France, Ireland, Serbia and Norway were presumed dead.

Consulted by one team involved in the climb, Mr. Warner said he told them his team used 2,500 feet of rope from Camp 4 to the summit. From his discussions with climbers worldwide after the tragedy, he said the fury of nature along with three tactical errors led to the deaths, including those of four very experienced climbers he knew well.

Mr. Warner said errors made before the avalanche included misplacing ropes and underestimating how much rope was needed for the push to the summit. As much as 18,000 feet of rope are secured to the slope to assist climbers up the slope and left in place for the descent, he said.

A second mistake involved beginning the ascent to the summit at 3 a.m., which meant reaching the summit at 8 p.m. That meant making the more dangerous descent in the dark, made all the worse by descending into the shaded side of the mountain.

A third tactical error involved the fact that some climbers had no radios and satellite phones, which Mr. Warner said are necessary to maintain contact with fellow climbers and base camps.

Then nature unleashed its fury.

A serac -- a column of ice the size of an automobile with climber's ropes likely attached to it -- peeled off the mountain and swept the ropes and climbers away in an avalanche.

"There definitely were some tactical errors," Mr. Warner said, citing human error as the prime cause of most climbing deaths. "But ultimately it was an avalanche that killed them. An ice fall is impossible to predict. This was an absolute tragedy when the ice broke loose and tore out the ropes."

A helicopter plucked two frostbitten Dutch climbers from K-2 yesterday, but the rescue of an Italian climber was delayed until today. One rescued climber, Wilco Van Rooijen, blamed mistakes in preparing for the final ascent -- not just the avalanche -- for one of mountaineering's worst disasters.

Gerard McDonnell, 37, became the first Irish climber to climb K-2 on Friday, but is believed to have died during his descent. The death toll was the largest ever on K-2.