There were 13 Breeders' Cup races run without incident over the last two days at Santa Anita Park.
But in the 14th and final race, the Classic, Vino Rosso's win was overshadowed by the breakdown of Mongolian Groom, a 4-year-old gelding who was vanned away after pulling up and not finishing.
The Breeders' Cup later announced horse had been euthanized. "The death of Mongolian Groom is a loss to the entire horse racing community. Our equine and human athletes' safety is the Breeders' Cup's top priority," the organization said in a statement.
Santa Anita has been the site of 37 horse deaths during racing and training since last Dec. 26.
Mongolian Groom was in contention -- swapping between second and third -- with about a quarter-mile remaining in the 1 \-mile race. At the top of the stretch, he was in third place when the jockeys aboard the horses in front of him both suddenly turned to look back -- possibly reacting to a sound. Moments later, Mongolian Groom was suddenly pulled up by jockey Abel Cedillo.
Breeders' Cup officials said the horse suffered a "serious fracture to his left hind limb."
The winner of the $6 million race, Vino Rosso, is a 4-year-old colt who won the Gold Cup in his only other start at Santa Anita in May. But Saturday's win in the $6 million Classic was by far the biggest of his career. He was ridden by Irad Ortiz, Jr., who also rode winners in the Turf championship and Dirt Mile.
Vino Rosso paid $11.20 to win, $5.80 to place and $4.00 to show. The favorite, McKinzie, was second and paid $4.80 and $3.60. Higher Power paid $6.00 to show.
Bricks and Mortar started the day as the leading horse of the year candidate and will also end it that way.