Um, Im not sure try this website
http://www.infoplease.com/encyclopedia/us/washington-state-united-states-geography.html
Cliffs are very heavy rocks and when there is too much weight it can cause cracks that weakens the structural integrity which can cause the cliff to either collapse or give way, falling on the ground below which can kill people crush cars or block roads. Hope this helps :)
Answer:
a mass or collection of things; an assemblage
Explanation: