Trafikplasten, Furuviksparken, Gävleborg, Sweden

A 31-year-old man was hospitalized with blood poisoning and internal injuries after he boarded the kiddie car ride in an attempt to assist his daughter and his rectum became impaled on a tow hitch that protruded from behind the vehicle. Source (in Swedish)

Trafikplasten Furuviksparken Accident
Ride vehicle with tow hitch (which have since been removed).