An avalanche in California's Sierra Nevada mountains has killed at least eight skiers, making it the fourth deadliest avalanche in US history. The slide occurred on Tuesday in the Castle Peak area near Lake Tahoe, a region where deadly avalanches are not uncommon, according to the Sierra Avalanche Centre.
The centre has recorded at least 50 avalanches in the Lake Tahoe area since September 2025. Fatal avalanches have occurred in six of the past ten years, including a snowmobiler killed earlier this year in the same Castle Peak area. Other incidents include a backcountry tourer on Powderhouse Peak in February 2025 and two riders caught on KT-22 in January 2024, killing one.
Perhaps the most infamous avalanche in the region was the 1982 Alpine Meadows slide, which killed seven people, including four employees who remained on site despite the resort's closure. That disaster was documented in the film 'Buried: The 1982 Alpine Meadows Avalanche' and the book 'A Wall Of White'.
Avalanches occur when fresh snow falls on a refrozen icy layer, creating a weak base. Dr Nathalie Vriend, associate professor at the University of Colorado Boulder, explained that granular, icier snow forms a weak layer that can shear under new snowfall. Tuesday's avalanche was triggered by a persistent weak layer covered by a large load of snow, said Chris Feutrier, forest supervisor of Tahoe National Forest.
The National Avalanche Centre currently rates the Lake Tahoe area as level four out of five on the North American Public Avalanche Danger Scale, indicating very high risk. The weak layer that caused the slide remains and has been reloaded with another three feet of snow, officials warned.
