An event resulting in great loss is known as _________.

A. Calamity
B. Tragedy
C. Disaster
D. All of these

An event resulting in great loss is known as a catastrophe.

Where Calamity, Tragedy, Disaster etc are synonymous with each other.

Other synonyms are a disaster, catastrophe, mishap, misadventure, mischance, misfortune, blow, adversity, scourge, reverse, trial, tribulation, affliction, distress, tragedy, ruin, downfall, trouble, woes, sword of Damocles