If water goes under a required level a vacuum can form underneath the lining which makes the whole structure unstable.
Gravity.
Gravity.
fatigue
Colony collapse is when bees mysteriously disappear. Vampire mites and nicotine-based insecticides are among the possible causes.
Causes of collapse for which rescue breathing may be needed are anaphylactic shock, heart attack, and poisoning.
pickles
The collapse of a star is based on its age. When it runs out of "Fuel" its inside contracts as the outside expands. it can then super nova or collapse into a tiny star.
high potassium causes arrhythmias and the arrhythmias that it causes can reduce blood pressure causing someone to collapse.
Something blocking it
The roofs of these caves collapse
Its defeat and takeover by Alexander the great.
causes buildings to collapse