meltdown vs tragedy

meltdown and tragedy both are nouns.

Word	Noun	Adjective	Verb	Adverb
meltdown	Yes	No	No	No
tragedy	Yes	No	No	No

As nouns, tragedy is a hypernym of meltdown; that is, tragedy is a word with a broader meaning than meltdown:

Other hypernyms of meltdown include calamity, cataclysm, catastrophe, disaster.

meltdown (noun)	tragedy (noun)
a disaster comparable to a nuclear meltdown	drama in which the protagonist is overcome by some superior force or circumstance; excites terror or pity
severe overheating of the core of a nuclear reactor resulting in the core melting and radiation escaping	an event resulting in great loss and misfortune