When a freak inbounds avalanche swept a 13-year-old boy to his death at Nevada's Las Vegas Ski and Snowboard Resort last season, Doug Abromeit, director of the U.S. Forest Service's National Avalanche Center, was shocked. When a second fatal inbounds slide hit Colorado's Arapahoe Basin four months later, Abromeit—like other avalanche experts—simply shook his head in disbelief. In the 20 years that he's worked at the National Avalanche Center in Ketchum, Idaho, there have been three inbounds avalanche deaths. As far as two inbound fatalities in one season, "It has never happened, Abromeit says.
While inbounds avalanches are like shark attacks—rare but unnerving—last season's two fatalities have prompted a major review of safety protocols at U.S. resorts nationwide. "They were a real wake-up call, one U.S. Forest Service official says. Investigations of the slides will probably result in stricter policies: "Here's the equipment you need, here are the procedures you should have in place, says Ed Ryberg, recently retired Forest Service National Winter Sports Program leader.
The first avalanche hit after a series of January '05 storms dropped seven feet of snow in Nevada's Spring Mountains. At about 3 p.m., a 15-foot-deep, three-quarter-mile-wide section of a headwall tore away at the tiny 40-acre resort. Witnesses shouted to be heard above the roar as the collapsing mountainside sped toward the No. 2 lift. Allen Brett Hutchison, a middle-school student, was riding alone in the chair, so nobody knows exactly what happened next, but investigators believe violent wind gusts in front of the speeding wall of snow blew the chair sideways and knocked Hutchison off the lift. Four chairs back, two skiers held on for their lives and were probably saved by a knoll that diverted the avalanche.
The second slide struck in late May. David Conway, 53, a lifelong skier who lived in Boulder, Colo., with his wife and two daughters, drove to A-Basin to enjoy balmy spring conditions. At about 10:30 a.m., a 300-foot-wide slab of wet snow in First Alley, an expert chute, fractured and raced 1,000 feet down the hill, carrying Conway into trees that border the run.
Safety experts emphasize keeping the dangers of inbounds slides in perspective, noting that of the nearly 450 avalanche fatalities reported in the past 20 years, less than 1 percent were on resort slopes. To be safe, skiers are told to stay within the ropes—where terrain is controlled. So what went wrong at Las Vegas and A-Basin?
To find out, the Forest Service formed Incident Review Teams composed of a who's who of leading experts in avalanche study, including Abromeit and the legendary Chuck Knox, recently retired from the Colorado Avalanche Information Center. Like investigators made famous in television shows such as CSI, Knox and Abromeit are forensics experts. They re-create deadly slides from technical data and obscure clues, such as fracture lines, shear strength and recrystalization patterns. "We try to learn what happened and why, says Abromeit, "and then try to ensure that it never happens again.
The Incident Review Team hadn't released its report on the Las Vegas accident at press time, but several factors stand out: The resort didn't do any avalanche control above chair No. 2—and has never done any there in the ski area's 40-year history; the New Year's storm cycle created dangerous conditions that, perhaps, have never before been seen in the area; and the chairlift didn't have a safety bar, which might have prevented Hutchison from falling out.[NEXT]The resort closed for five weeks after the accident to evaluate safety procedures. The incident also prompted Powdr Corp., which owns the Las Vegas ski area, along with Utah's Park City Mountain Resort, among others, to review safety measures companywide.
The Forest Service oversees ski areas on public lands and requires them to submit avalanche safety plans, but carrying out these procedures is the responsibility of eeach area. "It's our job to ensure we're doing enough control work to maintain the highest level of safety, says Rick Sramek, director of mountain operations at Breckenridge, Colo., which installed the highest chairlift in North America this season, serving steep, avalanche-prone terrain.
At Breckenridge, and other big resorts, every day begins with a dawn meeting with the safety coordinator and ski patrol director. Patrollers fan out to dig snow pits, assess danger levels, drop bombs and close slopes deemed unsafe. Despite all the expertise, Sramek adds, "avalanche control is as much an art as a science. Evaluating slide risks across thousands of acres of terrain is a daunting task.
Unlike the Las Vegas accident—a traditional headwall avalanche that Ryberg says was foreseeable—the A-Basin slide was more ominous. Classified as a "wet slab avalanche, it began inbounds on well-skied terrain. Wet slabs generally occur in the spring, when warm daytime temperatures cause meltwater to trickle to the ground, weakening the slab's bond with the mountain. If a slab fails to re-freeze at night, it can slide. Wet slabs, which are similar to mudslides in density, are a nightmare for resorts because explosives are ineffective at clearing the soggy tons of snow. They are also poorly understood.
According to the Incident Review Team's report, A-Basin's avalanche protocols were up to standard but didn't specifically address wet-slab conditions. Because of Conway's death, the Forest Service has launched a new study of wet-slab slides. "Everybody is interested in figuring out if we can predict them, Abromeit says. The study could result in more springtime trail closures and lead to new techniques for controlling slopes in warm weather.
Inbounds avalanches also raise new legal questions. State laws such as the Colorado Ski Safety Act immunize resorts from liability for "inherent dangers and risks of skiing. But the law makes no mention of inbounds avalanches. "I think most people would assume they're not going to get caught in an avalanche on the slopes, says Denver attorney Jim Chalat, who is representing Conway's family. Nonetheless, inbounds avalanche injury remains an extreme rarity. "The best way to avoid an avalanche is to stay on groomed slopes, Abromeit says, noting the array of safety technology employed by the ski-resort industry.
But risk is inherent in skiing. "You can never reduce the probability of an avalanche to zero, Abromeit says. "If the slope is steep enough, and the conditions are right, it will slide.