The straw that broke the donkey's back phrase
Used to allude that the last force, problem or burden which is seemingly minor and small causes a person, system or organisation to collapse or fail
That lie was the straw that broke the donkey's back and the boss decided to fire him.
Her husband's violent act last night was the straw that broke the donkey's back and she left him.
If something is more than flesh and blood can bear, endure, etc., it is unpleasant, painful, or offensive than one is able to tolerate or endure.
To fall suddenly and heavily to the ground
The biggest building was caved in last night due to the historic storm ever.