Size
The worst avalanche of modern times occurred in Yungay, Peru, in 1970 when an estimated 20,000 individuals perished as the force obliterated their village. The avalanche was a mile wide and 10 miles in length and happened in the Andes Mountains.
History
Avalanches in the Alps during the time of Hannibal, around 218 B.C., reportedly killed thousands of soldiers while an avalanche that occurred in 1618 in Plurs, Switzerland, killed 2,427 citizens.
Cause
The Swiss, Italian and Austrian Alps were the scene of frequent fatal avalanches as a result of the high amounts of precipitation during the incredibly snowy winter of 1950 through 1951, with over 265 people dying in these events.
Transportation Tragedy
On March 1, 1910, an avalanche claimed the lives of 96 railway passengers in Washington State's Cascade Mountains when it swept a pair of trains off the tracks and into a ravine.
American Avalanches
The Mountain Rescue Association website states that between the years 1950 and 2001, some 491 people fell victim to avalanches within the United States.