A 29-year-old skier was killed Thursday afternoon in Alpine Meadows, Calif., when an avalanche swept him down a mountain and slammed him against a tree, local NBC station KCRA reported. The man and two friends had been skiing in rugged terrain when a wave of snow knocked them downhill. One of his friends called for help at 2:50 p.m., and rescue teams arrived an hour and a half later, after taking a snowcat and then hiking half a mile to the unstable site. "We had to unwrap him from around some trees and stuff and dig him out a bit more," one search team member told the local ABC station. The man was rushed to Tahoe Forest Hospital in Truckee but died later. The man's death comes on the heels of a wave of fatal accidents, many involving avalanches, that have befallen skiers and drawn attention to the dangers of extreme skiing.