accident

nouns

an unfortunate mishap; especially one causing damage or injury
accident
is a type of (narrower)
an instance of misfortune
misadventure, mischance, mishap
anything that happens suddenly or by chance without an apparent cause
"winning the lottery was a happy accident"; "the pregnancy was a stroke of bad luck"; "it was due to an accident or fortuity"
accident, chance event, fortuity, stroke
is derived from
accidental