New Zealand Avalanche Kills 4

An avalanche swept down New Zealand's second-tallest peak Wednesday, flinging climbers over a thousand feet and leaving at least four dead and two others injured.

The climbers plunged 1,640 feet when the avalanche hit Mount Tasman about 8:30 a.m. Wednesday, said spokeswoman Gail Adams of Garden City Rescue Helicopter, which dispatched helicopters to the mountain.

Two of the four killed were New Zealanders and two were Australian, a police spokesman said on condition of anonymity. Three of the victims were climbing guides. Two Swiss climbers also were caught in the avalanche, but were unhurt, police said.

Such an avalanche during Mount Tasman's climbing season - the November-through-April period that straddles the Southern Hemisphere summer - is unusual and it is not immediately clear what triggered the slide.

Police imposed a no-fly zone over the mountain to prevent the vibrations of passing flights from triggering additional avalanches. They sent rescue teams and sniffer dogs to Mount Tasman to search for more climbers, although no other climbers were believed to be in the area of the slide, emergency officials said.

The 11,473-foot high Mount Tasman is about 500 miles southwest of the capital, Wellington, and stands in the Mount Cook National Park on New Zealand's South Island.

Initial reports erroneously said the avalanche occurred on Mount Cook, which is New Zealand's highest peak.

Avalanches are common in New Zealand's alpine areas, but usually take place while temperatures are rising following mid-winter, a geological expert said.

"They generally occur as the snow pack becomes unstable, particularly mid-winter onwards where there has been heavy snowfall or areas of melt or instability within the layers of snow," said David Barrell from the Institute of Geological and Nuclear Sciences.

Climbing Mount Tasman takes about 7 days, depending on the weather. Its icy peak is highly glaciated. First scaled in 1895, Mount Tasman is described by alpine guides as "an ice climber's dream," requiring exceptional skill.

"Every ridge to Mount Tasman's summit is a sinuous ice climb that requires excellent technique," the Alpine Guides website says. "The climb is more technical than an ascent of Mount Cook. It is a serious and committing climb."

By Steve McMorran