Section 18 in THE BHARATIYA NYAYA SANHITA, 2023 – BNS

Accident in doing a lawful act.

18. Nothing is an offence which is done by accident or misfortune, and without any
    criminal intention or knowledge in the doing of a lawful act in a lawful manner by lawful
    means and with proper care and caution.
    Illustration.
    A is at work with a hatchet; the head flies off and kills a man who is standing by. Here,
    if there was no want of proper caution on the part of A, his act is excusable and not an
    offence.