The families of six mothers, wives and "passionate, skilled skiers" killed in a California avalanche are mourning their deaths and grappling with "many unanswered questions" about the tragedy, they said Thursday.
Carrie Atkin, Liz Clabaugh, Danielle Keatley, Kate Morse, Caroline Sekar and Kate Vitt were all friends "who cherished time together in the mountains," their families said in a statement.
They were part of a 15-person group on a two-night backcountry trip to California's Sierra Nevada that ended in the worst backcountry ski avalanche in the sport's history Tuesday.
"They were experienced backcountry skiers who deeply respected the mountains. They were trained and prepared for backcountry travel and trusted their professional guides on this trip. They were fully equipped with avalanche safety equipment," the statement said.
Two other friends who were on the trip survived and were rescued along with four other people, including a guide. The three others who are dead or presumed dead were guides.
Rescuers were unable to recover the bodies Thursday.
"Due to hazardous weather conditions, avalanche victims cannot be safely extracted off the mountain today," said Ashley Quadros, a Nevada County sheriff's spokeswoman.
More than a foot of snow was expected late Thursday in the Lake Tahoe area, according to forecasts from the National Weather Service.
"Recovery efforts are expected to carry into the weekend," Quadros wrote.
The women's deaths Tuesday have shaken not only their loved ones, but also the Tahoe region and the broader ski and mountain guiding community, which is reckoning with a wave of questions about what happened and what went wrong.
"Anyone who is ski guiding right now, whether they're in the Sierra or a thousand miles from the Sierra, has this accident in mind," said Forest McBrian, a longtime mountain guide in Washington state.
Authorities are pursuing several lines of investigation as they seek to determine what went wrong.
Nevada County Undersheriff Sam Brown said Thursday that the sheriff's office was completing a coroner's investigation, working on a missing persons investigation and documenting its search-and-rescue operations. The agency has also notified labor law investigators of the incident.
"When you put all this together, it's a giant investigation from a lot of different angles," Brown said.
Avalanche experts with the Sierra Avalanche Center were also working on an investigative report to try to understand the factors that contributed to the tragedy.
Zeb Blais, the owner of Blackbird Mountain Guides, the company that organized the trip, said in a statement that investigations were "underway" but that it was "too soon to draw conclusions."
"We ask that people following this tragedy refrain from speculating. We don't have all the answers yet, and it may be some time before we do," he said.
Dallas Glass, an avalanche forecaster with the Northwest Avalanche Center, one of 24 such centers across the U.S., said the Sierra Avalanche Center's investigation could take weeks to complete.
"These reports, as you would imagine, are quite intensive," he said, adding that it took the Northwest Avalanche Center about a month to compile its report on a recent avalanche death in the Pacific Northwest. "It varies greatly, depending on workload and amount of information and storm tracks. ... They are still putting out the avalanche forecast."
McBrian said it would be unwise to draw conclusions from the information that is available at this point.
"Waiting for each new increment of information and analyzing it runs counter to our understanding of how accidents unfold," he said. "It's never one thing. It's nearly always, in retrospective debriefing, it's a cascade of events, and when there's a large group that seems even more true."
Among the key questions that remain: how the group assessed the weather and avalanche conditions, how it selected a route, whether the avalanche was triggered naturally or by a skier and how social pressures shaped decision-making.
Advertisement
Conditions and communications
The Sierra Avalanche Center puts out a regular forecast about avalanche conditions during the winter ski season. In this case, forecasters predicted high avalanche danger at all aspects and all elevations and noted that "natural avalanches are likely, and human-triggered avalanches large enough to bury or injure people are very likely."
With a storm forecast for the region well in advance, guides should have been expecting intense snowfall. On many guided trips, guides will carry satellite messaging devices for weather updates and more communications. It's not yet clear what Blackbird's guides were using in the field.
Glass said that forecasts are helpful but that seasoned mountain guides will often rely more on their own field observations to build their own forecasts.
"When you're out in the mountains, being out there for multiple days, there is actually some benefit to that, because you're watching the storm evolve in front of your eyes. You're getting constant information over the time period that you're out because you're in the storm, you're in the conditions," Glass said.
Guides typically discuss the forecast and risk management strategies in morning and evening meetings. Investigators will most likely probe the guides' decision to enter the backcountry Sunday, given the potential for extreme snowfall.
It's not unheard of for seasoned backcountry travelers to ski tour during a storm like the one that struck Tahoe on Tuesday — in the gentlest terrain.
"You can actually still move around in the mountains when there is an avalanche warning out, as long as you know you're out of avalanche terrain," Glass said. "For groups that are going out in these storms like this, the margins do become thinner."
Route
In an initial report, the avalanche center said the fatal slide occurred on a north-facing slope at an elevation of around 8,200 feet. The location is about a half-mile from Frog Lake Backcountry Huts. While the location was in low-elevation terrain less prone to avalanche starts, it was exposed to avalanche runout from steeper slopes above.
The location is near a common ski touring path on which to access the huts, but there are other routes the group could have taken, according tomaps from the Truckee Donner Land Trust, local skiers and guides.
A route that initially travels east down a valley and away from the huts might have better avoided avalanche terrain, but it could have taken much longer to travel, and it would have required the group either to exit to a different trailhead and find a ride or slog farther back to their vehicles.
"There would have been alternate routes. They just would have been a lot longer," said Marty Ylitalo, a longtime backcountry skier in the Tahoe area. "It would have been coordinating a bunch of vehicles and extending their time out there, potentially extending their exposure."
Investigators will probe how the group decided on its route and how it planned to minimize risk along the way. It's also possible the group might have strayed from its intended route or moved more slowly than anticipated because of low visibility in blizzard conditions, fatigue or navigation errors.
"Where did you choose to go? That is how we control or influence our exposure to avalanche hazards," McBrian said.
The trigger
An avalanche requires three ingredients: terrain where snow can slide, which is usually 30 to 45 degrees, unstable snow and a trigger.
The stress of a skier's weight on the snowpack is the most common trigger.
"We make really good triggers in the mountains," Glass said. "But we also know that avalanches can be triggered naturally. In this case, that natural trigger can be just simply the additional weight of more snow."
Avalanches can also be triggered remotely, meaning human disruption of the snowpack in one location causes a slide elsewhere, usually within a few dozen feet.
"The snowpack doesn't stop on that magic slope angle line, right? It's connected across the terrain," Glass said. "Remote triggers are generally pretty indicative of very unstable conditions."
As of Thursday evening, the Sierra Avalanche Center haslisted the trigger as unknown.
Group dynamic
A 15-person group is quite large for backcountry travel, and the same dynamics that complicate any social group are at play and sometimes intensified during trips to remote backcountry huts, with big safety decisions on the line.
"Group dynamics," Ylitalo said. "That would be a real strong factor."
"We're all so curious to hear the formal report to see why the decisions were made as they were."
