The colt River Derby sustained a catastrophic injury while training at Santa Anita on Wednesday morning, becoming the 27th horse to die in racing or training at the Southern California track since the season began Dec. 26.
River Derby, an unraced 2-year-old, suffered a fractured shoulder, his trainer, Ruben Gomez, told the Los Angeles Times. The horse's death was the fourth at Santa Anita since May 17.
"I am so sad," Gomez told the Times. "I ride my horses every day and I get so attached to them, especially my babies."
The track's previous fatality was Kochees, a 9-year-old gelding that was euthanized May 26 after injuring his left front leg.
People for the Ethical Treatment of Animals has called for racing to be suspended until an investigation by the Los Angeles County District Attorney's Office is completed.
"Derby River's death today at only 2 years old is yet another reason why people want to see an end to racing," PETA said in a statement Thursday, "but the least that must be done right now is for tracks to put scanning equipment in place to detect pre-existing leg and shoulder injuries and for measures to be taken to ensure that young horses aren't seriously injured before their bones are even mature."
Santa Anita is scheduled to host the Breeders' Cup Nov. 1-2. It is considered the biggest two-day event in U.S. horse racing.