So, I got an idea from sloping movables from Eric that he was working on.
For the sloping movables, I think it may be a perfect idea for the landslides on cliffs. Muddy and damaged movables have a tendency to cause landslides if there is one or more players standing on the cliff. The sloping movable will then fall down, and will kill players on the pitfalls or damage them after sliding down to the ground by +35%.
To avoid the landslide (when you're going down) killing you, use the jetpack and fly away from it just to avoid death.