15 people were caught in the massive avalanche on Castle Peak mountain on Feb. 17
Credit: Stephen Lam/San Francisco Chronicle via Getty
NEED TO KNOW
- The cause of death for all nine people who died in a Feb. 17 avalanche near Lake Tahoe has been revealed
- The slide was the deadliest in California’s history and the worst in the U.S. since 1981
- The cause of the avalanche remains unknown, but a report indicated that guides led the skiers below avalanche terrain in dangerous conditions
The cause of death has been revealed for all nine victims of a deadly avalanche near Lake Tahoe.
A 100-foot-wide wall of snow fell 400 feet down Castle Peak mountain in the Feb. 17 slide, which was the deadliest in California’s history and the worst in the U.S. since 1981.
There were 11 clients and four guides in the area when the avalanche struck, killing nine.
According to partially redacted reports shared by the Nevada County Coroner’s Office on Thursday, Aug. 6, all nine died from asphyxia due to being covered by snow, according to the San Francisco Chronicle

Credit: Nevada County Sheriff’s Office
Asphyxia, also called asphyxiation, is when the body doesn’t receive enough oxygen, per the Cleveland Clinic. Potential causes include drowning, strangulation, asthma and foreign objects blocking an airway.
The nine fatalities included three guides from Blackbird Mountain Guides and six clients, the Chronicle added. Five clients and one guide survived the avalanche.
By Feb. 21, all nine bodies had been recovered and identified.
The deaths happened after two groups of skiers decided to come together to return to the trailhead at the Castle Peak Snowpark on Donner Summit, a report from the National Avalanche Center stated.
One group consisted of eight women staying at the nearby Frog Lake huts and two guides. The other group comprised three males and two guides.

Credit: Stephen Lam/San Francisco Chronicle via Getty
The cause of the avalanche is still unknown, while the Nevada County Sheriff’s Office launched an investigation in the aftermath to ascertain whether criminal negligence played a role.
Findings from the National Avalanche Center’s report established that the guides led the skiers below avalanche terrain during dangerous conditions, and that larger groups are more likely to be caught in slides.

Credit: Nevada County Sheriff’s Office/Facebook
“Exposing only one person at a time to avalanche terrain is an accepted best practice for backcountry travel,” the report stated.
“Analysis of past avalanche accidents has indicated that larger group sizes (4 or more people) have a higher chance of being caught in avalanches.”
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The report also found that some members of the group wore avalanche airbag backpacks but none of them deployed.
PEOPLE reached out to the Nevada County Coroner’s Office and Nevada County Sheriff’s Office for comment, but did not immediately hear back.
Read the full article here
