fortuity, chance event, mishap, accidental, incident, collision, fatality, crash, accidence, wreck, more...

intention, purpose, design, deliberation, plan

car accident, plane crash, train wreck, boat accident, bicycle accident, motorcycle accident, pedestrian accident, airplane accident, more...

mere, serious, fatal, historical, unfortunate, terrible, happy, tragic, nuclear, cerebrovascular, pure

unexpected event,   minor mishap,   art studio mishap,   by bad luck,   recipe for disaster,   bad occurence,   child's mishap,   bad incident,   chance occurrence,   unplanned event