Upheaval.
First of all, upheaval is one word, not two. It means a violent disruption or change in something
fiery
The word "violent" is pretty mean.
turmoil
Coup d'etat means a sudden change of government by violent means.
The word root that means change is "morph."
The word violent forms the negative adjective nonviolent, the adverb nonviolently, and the noun nonviolence.There is also a seldom-used term "overviolent" meaning excessively violent.
You think probable to assassin.
metamorphosis
'un violent' means 'a violent' in French.
The word that means a sudden and violent collapse is "cataclysm." It refers to a large-scale and often violent event that leads to significant disruption or destruction. Cataclysms can occur in various contexts, including natural disasters, social upheavals, or catastrophic failures.
The Latin word for change is "mutatio."