A powerful avalanche near Donner Summit buried multiple skiers, prompting a risky rescue operation and highlighting what causes avalanches and how people can stay safe in such dangerous conditions.
Donner Summit Avalanche Incident What We Know So Far, What Causes Avalanches, and How to Stay Safe
The avalanche occurred on Tuesday morning in the Castle Peak region, near Donner Summit, after severe winter weather conditions resulted in heavy snowfall and strong winds in the region. The emergency services were notified of the distress situation at 11:30 a.m. after a call was received about several skiers being buried under deep snow. Nearly 50 rescue personnel were sent to the region, who had to work in extremely dangerous conditions with poor visibility, strong winds, and the possibility of another avalanche. Six members of the group were rescued after several hours of searching.
Two were hospitalized for injuries, with one being released from the hospital on Tuesday night and the other expected to be discharged on Wednesday, officials said. Such incidents bring to light the dangerous and unpredictable nature of avalanches.
An avalanche is a sudden flow of snow down a slope, most commonly occurring in mountainous or remote backcountry areas. According to the National Avalanche Center, watching weather forecasts, carrying proper safety equipment, and getting the right training are critical for anyone traveling in avalanche-prone terrain. On average, about 25 people die in avalanches each year in the United States. As the center notes, “Some days are dangerous and some days are not.”
Avalanches require two basic conditions: a slope of 30 degrees or greater and multiple layers of snow. When additional pressure is applied, such as from new snowfall, wind, rain, or even human activity, the weak layers of the snowpack can separate and move down the slope.
There are a number of different kinds of avalanches. Sluffs are made up of loose snow and do not cause much damage. Slab avalanches occur when a thick layer of solid snow breaks loose, and these are the most deadly type of avalanche. Another type of avalanche is a cornice avalanche, which occurs when the wind creates a snow overhang on a ridge.
Avalanches may be caused by sudden movement, fast weather changes, or strong winds. However, avalanche experts claim that 90% of avalanches that result in injuries and deaths are caused by the movement of the victims themselves or the group they are with. This is why it is important for skiers, snowboarders, snowmobilers, and hikers to check the avalanche forecast and be equipped with the right safety equipment.
In ski resorts, avalanche danger is mitigated by safety measures that include testing the stability of the snowpack and conducting controlled explosions to unleash unstable snow before opening the slopes, according to avalanche experts.
It is not possible to outrun an avalanche. Dry slab avalanches can go as fast as 80 mph, and wet avalanches go about 20 mph. Most people who get caught in an avalanche are already on the mountain when it occurs, which is why it is much more effective to prevent an avalanche from happening than to try to escape one.
Safety professionals recommend checking avalanche forecasts at avalanche centers or avalanche.org, making sure to have a buddy with you, and having the proper gear. This gear should include an avalanche transceiver or beacon, a shovel, and a probe to find people who are buried. Avalanche airbag backpacks can also be used to keep the user closer to the surface of the avalanche. Taking a course in avalanche safety and wilderness first aid is highly recommended.
The Lake Tahoe avalanche is just one of the many fatal avalanches that have occurred in the past few years. In January of 2026, a snowmobiler was killed when he was buried under an avalanche in the Sierra Nevada. In June of 2025, a skier died on Mount McKinley in Alaska after he set off an avalanche while skiing down the mountain. Earlier that year, a snowmachiner was buried 10 feet deep in a massive avalanche in the Chugach National Forest, and three heli-skiers were killed near Girdwood when they were caught in an avalanche while skiing backcountry.
These events, among others, demonstrate how quickly the situation can become fatal.
