Report: Three of six Tahoe avalanche survivors buried in snow before rescue

Three of the survivors of last week’s deadly avalanche near Lake Tahoe were buried under the snow before being dug out by their fellow skiers in the moments after the disaster, according to an initial avalanche occurrence report from the Sierra Avalanche Center.

The rescue under Perry’s Peak would have been harrowing, experts said, as those on the surface typically only have about ten minutes to locate and dig out avalanche survivors — possibly already wounded by blunt-force trauma as they were swept up by a wall of snow — before they run out of oxygen and asphyxiate. With 12 skiers buried under the snow and only three on the surface, it would have been highly unlikely they could all be located alive.

“That would be extremely difficult,” said Robert Rice, a UC Merced associate professor and former avalanche forecaster. “Digging through avalanche snow is very, very difficult.”

The report was based on data collected in recent days once weather conditions allowed responders to reach the mountain where nine people were killed in the deadly slide.

It also confirmed that the avalanche was a soft-slab avalanche, which “relates to the new snow,” Rice said. A soft-slab avalanche could have either involved the new snow itself failing, or the weaker layer underneath failing and releasing the new snow on top. Those scenarios could either be triggered by new snow falling on existing snow; a cornice, or mass of hanging snow, falling; or a human trigger.

The group of backcounty skiers and their guides had been making its way back from a three-day trip to the remote Frog Lake huts on Feb. 17 when they were struck by the avalanche around 11:30 a.m. Amid near-whiteout conditions, rescuers made it to the scene that evening to find six survivors who had been able to locate three of their deceased companions. The survivors were transported off the mountain, but recovery operations for those left on the mountain were delayed for several days due to continuing severe weather and avalanche danger.

The bodies of the nine deceased skiers were recovered by rescue teams on Friday and Saturday after avalanche mitigation. The nine victims included six women who were part of a group of friends described by their families as skilled skiers who were “connected through the love of the outdoors.” The three other victims were guides with Blackbird Mountain Guides, the company leading the trip.

Police on Saturday had reported that initial information suggested two people at the rear of the group had avoided the slide. According to the avalanche center, the 400-foot-long slide caught 12 members of the party and buried them completely.

Much of the known information about conditions in the area comes from forecasters who went out to the scene alongside rescue workers, but even that was not possible until several days after the avalanche, said Andy Anderson, an avalanche forecaster with the Tahoe National Forest Sierra Avalanche Center. Further details were provided by rescue team members.

“We still do not have all the information that we hope to get,” Anderson said. “Some of it we’ll never get just because of the conditions and the circumstances surrounding that event.”

The slope where the avalanche occurred was located beneath Perry’s Peak, a steep slope east of Castle Peak, dotted with trees except for the gap of white face where the avalanche began, according to the report. Authorities reported that a skier had time to shout “Avalanche!” before the group was overtaken. The three skiers who were not trapped in the avalanche then began a companion search and were able to rescue three of the victims alive, the report said.

“It can happen very quickly. It can overwhelm them without any warning whatsoever,” Rice said. “You really don’t have time to react.”

The avalanche that hit the party was rated by the center at 2.5 on the classification scale for destructive potential, with a 2-class slide capable of burying people, and a 3-class avalanche capable of smashing trees or destroying a small building.

The harrowing search for the surviving skiers would have started with those who were not buried taking stock of who was swept away, Rice said. They then would have to ensure the terrain is safe for the others to carry out a rescue.

“This is all (in) seconds,” Rice said.

All the skiers on the trip were equipped with avalanche beacons, which would then be set to “receive” mode, to pick up the beacon signals of those buried and allow the searchers to locate them. Those signals are used to get as close as possible to victims, when probe poles are then used to locate them in the snow, Rice said.

Once they’re located, digging to reach them can take minutes to an hour, depending on the depth of the snow.

The avalanche is still under investigation, with both the Nevada County Sheriff’s Office and the state’s Division of Occupational Safety and Health running separate probes. Due to the weather conditions, the forecasters were not able to collect any information on the pit profile of the avalanche, which allows them to view the snowpack layers making up the avalanche’s slab and to determine which layers failed, Anderson said. They also have no photos of the avalanche and have not yet spoken with any of the survivors.

“It kept storming for a few days after the avalanche, and so all of that stuff has been buried by new snow and no longer exists, basically,” he said. “We don’t see where the avalanche broke anymore – it’s just filled back in with snow. We can’t tell which layer broke – it’s just filled back in with snow.”

“We may not ever get that detail of information,” he added, “simply because the storm erased it.”