AD Camille Z, Athina Onassis’s 11-year-old Belgian-bred Zangersheide mare, was involved in an accident on December 11th during the Credit Suisse Grand Prix in Geneva, SUI.

The pair fell at an oxer and the mare shattered her upper hind leg. It took 45 minutes to tranquilize the horse and remove her by ambulance to a veterinary facility, where the decision to euthanize was made.

The 29-year-old Greek heiress, who is married to Brazil’s four-time Olympian Alvaro “Doda” Affonso de Miranda Neto, was unharmed in the fall.