LOUISVILLE, Ky. — A 3-year-old horse training for a final Kentucky Derby prep race has been euthanized after collapsing during a workout at Churchill Downs.

Tiz Chrome's trainer Bob Baffert said the colt suffered a fatal fracture of the left front sesamoid during a workout Sunday morning. Tiz Chrome was scheduled to run in the Derby Trial on Saturday.

Baffert said the colt was working with another horse and the two were heading into the far turn on the one-mile track when the injury occurred and Tiz Chrome fell, sending exercise rider Dana Barnes tumbling to the track surface.

Barnes was not injured.

Owned by the Lanni Family Trust, Mercedes Stable LLC and Bernard Schiappa, Tiz Chrome earned $67,850 with two wins in three starts.