10 Deadliest Avalanche Disasters, Including One With 20K Casualties

Avalanches remain among the most destructive natural disasters in mountainous regions. Heavy snowfall, steep terrain, and shifting weather conditions can create unstable snow that collapses without warning.

Around the world and across U.S. history, avalanches have killed thousands. The events below rank among the deadliest ever documented.

1970 Huascarán Avalanche – Peru

1916 White Friday Avalanches – Italy and Austria

1910 Wellington Avalanche – Washington, U.S.

1898 Chilkoot Trail Avalanche – Alaska, U.S.

1954 Blons Avalanches – Austria

1999 Galtur Avalanche – Austria

2017 Rigopiano Avalanche – Italy

1981 Mount Rainier Avalanche – Washington, U.S.

2026 Castle Peak Avalanche – California, U.S.

1982 Alpine Meadows Avalanche – California, U.S.

On May 31, 1970, an earthquake triggered a massive ice and rock slide from Mount Huascarán. The avalanche struck towns below and buried Yungay under a wall of snow and debris.

Estimates place the death toll between 15,000 and 25,000 people killed, making it the deadliest avalanche in history.

During World War I, heavy snowfall destabilized slopes in the Alps. On Dec. 13, 1916, multiple snow slides caused an estimated 2,000 casualties. It remains one of the most deadly mountain disasters ever recorded.

Near Stevens Pass in Washington state, two trains were stuck during a powerful storm. An avalanche occurred overnight and snow swept the railcars into a gorge.

A total of 96 people were killed, making it the deadliest avalanche in U.S. history.

During the Klondike Gold Rush, a slide along the Chilkoot Trail buried prospectors traveling north. More than 60 lives were lost. The deadly event marked one of the worst natural disasters of the gold rush era.

A series of slides struck the village of Blons after heavy snowfall. The avalanche struck homes and buried much of the town.

Some 57 residents died in what became one of Europe’s most deadly alpine disasters.

An avalanche near the village of Galtür roared down at high speed after extreme weather conditions. All in all, 31 people were found dead. The event led to expanded avalanche defenses and updated hazard zoning practices across the region.

Heavy snowfall and seismic activity preceded a slide that buried a mountain hotel. In the end, 29 people were killed. Search and rescue crews worked for days in dangerous conditions to recover victims and rescue survivors.

Ten climbers and a guide were killed near the Ingraham Glacier on Mount Rainier Washington. Several were rescued, but some remains missing after the deadly mountaineering accident, making it one of the most deadly mountaineering accident events in recent U.S history.

In the Castle Peak area near Soda Springs and Lake Tahoe, an avalanche killed at least eight backcountry skiers during a winter storm.

Authorities—including the Nevada County Sheriff’s Office and search and rescue teams—responded as the Sierra Avalanche Center warned of unstable snowpack in the Sierra Nevada.

On March 31, 1982, a California avalanche struck Alpine Meadows Ski Resort near Lake Tahoe in the Sierra Nevada. Seven people were killed after snow swept buildings and lift areas.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.