• incidence, incident, occasion
• homicide by misadventure
• chance meeting, encounter
• by a happy chance, by a lucky chance
• chance so ordained it that
• accidentally, at a venture, at random, by any chance, by chance, by coincidence, by luck, by misadventure, eventually, fortuitously, haphazard, haphazardly, happily, inadvertently, perchance
• contingency, contingent, fortuity, happenstance