(CNN) A horse died Sunday at Santa Anita Park in California after sustaining an injury in a race, a racetrack spokesman said.

Kochees was injured during his sixth race on Saturday, according to the spokesman, Mike Willman. He declined to say what injury the horse suffered.

Kochees' trainer and owner, Jerry Hollendorfer, declined to comment when reached by CNN on Sunday.

In a statement, People for the Ethical Treatment of Animals said, "Santa Anita and all California tracks must suspend racing until the ongoing investigation by the district attorney is complete and the new rules have been strengthened."

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