catastrophe

(noun) an event resulting in great loss and misfortune. Synonyms: calamity, disaster, tragedy, cataclysm. Examples: "The whole city was affected by the irremediable calamity." "The earthquake was a disaster."

(noun) a state of extreme (usually irremediable) ruin and misfortune. Synonyms: disaster. Examples: "Lack of funds has resulted in a catastrophe for our school system." "His policies were a disaster."

(noun) a sudden violent change in the earth's surface. Synonyms: cataclysm.