Pakistan ? The last survivor of the deadliest mountaineering disaster to hit K2 limped into base camp with frostbitten feet Tuesday, but thick clouds threatened to keep him on the mountain for at least another night.

“Now I really realize that everyone here has died,” said Italian climber Marco Confortola, 37, who was stranded on the world’s second highest peak after an avalanche of falling ice blocked climbers descending from the summit nearly four days ago.

As many as 30 mountaineers began their ascent of K2 on Friday. Eleven died in the avalanche that swept some climbers away and left others stranded in frigid conditions just below the 28,250-foot summit: three South Koreans, two Nepalis, two Pakistanis and mountaineers from France, Ireland, Serbia and Norway.

“I am happy to be alive,” Confortola told Everest-K2-CNR, an Italy-based high-altitude scientific research group, during a phone call from K2’s advanced base camp on the Pakistani side of the mountain at about 17,000 feet.

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.