A helicopter lifted two frostbitten climbers from the world's second-highest mountain, K-2, on Monday after an avalanche at more than 26,250 feet (8,000 meters) left at least 11 people missing and feared dead. The helicopter brought Dutchmen Wilco Van Rooijen and Cas Van de Gevel from K-2's base camp to a military hospital in Skardu, the nearest town, said Maj. Farooq Firoz, an army spokesman. He said Italian Marco Confortola, also believed to be suffering frostbite, was still struggling down the mountain on Monday. It was unclear when he would be low enough for a helicopter pickup, the Associated Press reported. Thin air generally prevents choppers from flying above 19,700 feet (6,000 meters).