avalanche
noun
a large mass of snow, ice, etc., detached from a mountain slope and sliding or falling suddenly downward.
Used to express a completed action that took place before another specific past action occurred.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
After we had got by and were continuing on our way down to Süs, we turned along an outstanding buttress of cliff and saw that some two miles of steep slope ahead had avalanched.
From Ski-running by Katharine Symonds Furse