LOS ALAMITOS, Calif. — An unraced 2-year-old colt trained by Bob Baffert was euthanized after an accident at Los Alamitos, becoming the 10th horse to die at the Southern California track this year.

Officials at the track in Orange County said Rapacious had completed his morning workout Tuesday when he reared up twice as he was about to exit the track. The colt lost his balance and fell on his back. The exercise rider wasn’t hurt.

After being examined by veterinarians, the colt was euthanized because of his back injury, track officials said. The California Horse Racing Board has yet to classify the cause of death.

The colt, owned by SF Bloodstock, Starlight Racing and Madaket Stable, had not make his racing debut.

“Los Alamitos remains committed to horse and rider safety and is conducting a full review of this incident,” the track said in a statement.

The track took steps to address safety after four horses died over 11 days earlier this year.

Of the 10 deaths at the track, four have involved thoroughbreds. The other six were quarter horses, which also race at Los Alamitos, according to the CHRB’s list of equine fatalities.