Multiple choice general knowledge I'm sure he didn't mean to break the window. It must have happened _____. by accident from accident to accident in accident Reveal answer Fill a bubble to check yourself A Correct answer Explanation 'By accident' is the standard English idiom for something happening unintentionally. The window break occurred without intent. 'From accident', 'to accident', and 'in accident' are not idiomatic English expressions for this meaning.