ISLAMABAD, Pakistan — Limping through ice on frostbitten feet, the last survivor of the mountaineering disaster that killed 11 climbers on K2 reached base camp Tuesday as cloud and snow prevented a helicopter rescue.

"Now I really realize that everyone here has died," said Marco Confortola, who was stranded on the world's second highest peak after an ice fall nearly four days ago.

"I am happy to be alive," the Italian climber told the Everest-K2-CNR, an Italy-based high-altitude scientific research group, during a phone call from base camp.

K2, which straddles Pakistan and China in the Karakoram range, is regarded by mountaineers as far more challenging than Mount Everest, the world's highest peak. K2's knife-edged ridges and icy slopes are steeper and prone to both avalanches and sudden and severe storms.

A huge serac, or column of ice, fell as climbers started descending after reaching the 28,250-foot peak summit late Friday. The ice swept away some climbers and ropes used in the descent, making it even more dangerous for those caught above in the frigid conditions.

On Monday, helicopters plucked two frostbitten Dutch climbers from base camp. As many as 30 climbers started the ascent on Friday and all are accounted for.

Confortola managed to descend to a camp at 19,000 feet on Monday, helped by three others, including an American climber. The Italian took food, fluids and oxygen, and then continued his climb down K2 on Tuesday.

"We don't give up, we look ahead," he said. "Now I just want to take off my shoes, my feet are pretty darn painful."

The group's spokeswoman, Francesca Steffanoni, said the mountaineer was examined by an American doctor and reported to be in good condition, despite his blackened, frostbitten toes.

Two Pakistani choppers have been standby at the nearest town of Skardu since Monday to retrieve Confortola, but were grounded because of the poor conditions. The base camp lies at just above 16,400 feet, considerably below the threshold at which they are able to fly safely.

"He (Confortola) is out of danger. He will stay at the base camp for a night, and the army's pilots will fly helicopters on Wednesday morning to rescue him if the weather has improved there," Pakistan tourism ministry official Shaukat Zaman said.

Pakistan has listed 11 climbers missing and believed dead: three South Koreans, two Nepalis, two Pakistanis and mountaineers from France, Ireland, Serbia and Norway.

One of the rescued Dutchmen, Wilco Van Rooijen, blamed mistakes in preparation for the final ascent — not just the avalanche — for one of mountaineering's worst disasters.

Van Rooijen told The Associated Press on Monday that advance climbers laid ropes in some of the wrong places, including in a treacherous gully known as "The Bottleneck," about 1,150 feet below the summit.

That caused hours of delays, so climbers only reached the summit just before nightfall. The column of ice fell as the fastest mountaineers descended.

Among the 11 listed as dead are Gerard McDonnell, a teammate of van Rooijen and the first Irish person to reach the summit of K2.

Friend Pat Falvey said McDonnell's family "are holding up well and are very proud of Ger's achievement and are still in total shock in relation to the fact that he may not be coming back."

He said they did not expect to get McDonnell's body back.

"At high altitude at over 8,000 meters (26,250 feet), it is too dangerous to mount a rescue to have the bodies returned," Falvey said.

About 280 people have summitted K2 since 1954, when it was first conquered by Italians Achille Compagnoni and Lino Lacedell. Dozens of deaths have been recorded since 1939, most of them occurring during the descent.

Associated Press writers Stephen Graham in Islamabad and Marta Falconi in Rome contributed to this report.