A. My friend told me about seeing massive rocks flying through the air; it sounded pretty dramatic to witness a major rock like that. b. While skiing in the mountains, we saw a huge where snow and ice mixed with rock fell and tumbled rapidly down the hillside into the adjacent valley.
c. The news reported a large amount of non-water saturated material moved downslope along a particular plane and deposited at the valley bottom where it temporarily dammed a river. That's the third reported this week following some heavy rains.
d. The moved from the flank of the volcano down into the valley, and depositing rock and debris that buried infrastructure much like when a river floods its floodplains.

1. fall
2. debris flow
3. avalanche
4. landslide
5. soil creep