accident

/ˈæksɪdənt ‍ˈऐक्‌सिडन्‍ट्‌/ noun [C]

an unpleasant event that happens unexpectedly and causes damage, injury or death दुर्घटना; घटना

I hope they haven’t had an accident.

a fatal accident [when somebody is killed]

IDM

by accident by chance; without intending to संयोग से, अकस्‍मात; बिना किसी इरादे के

I knocked the vase over by accident as I was cleaning.