Simple categories matching unintentional:

• error,
• injury,
• accident,
• feature,
• event,
• tort,
• force,
• signal,
• action,

Members with property unintentional:

• power-system_fault,
• vehicle_crash,
• motor-vehicle_accident,
• bike_accident,
• medical_error,
• wind,
• component_failure,
• automobile_crash,
• motor-vehicle_trauma,
• error,
• sound,
• sliver_face,
• motor-vehicle_collision,
• car_crash,
• mistake,
• bicycle_injury,
• motor-vehicle_crash,
• strong_wind,
• auto_accident,
• accident,
• natural_disaster,
• motor-vehicle_injury,
• plane_crash,
• habitual_behaviour,
• transport_accident,
• open_fire,
• carelessness,
• household_injury,
• car_accident,
• outdoor_cooking,
• traffic_accident,
• fixing,
• animal_bite,
• use,
• automobile_accident,
• smoking,
• clerical_mistake,
• road_traffic,
• crash,
• car_wreck,
• industrial_accident,
• burn,
• tone,
• pain,
• traffic_injury,