Arcadia, Calif. – Dramatic video captured a two-horse spill in the $100,000 San Simeon Stakes at Santa Anita on Sunday that led to the 23rd equine fatality at the Southern California track in just over three months. Arms Runner injured his right front leg and fell in the Grade 3 race on turf, two days after Santa Anita reopened to racing after being closed for nearly a month.

That caused a trailing horse, La Sardane, to fall. The 5-year-old mare got back on her feet and didn't appear to sustain any injuries. Jockey Ruben Fuentes didn't ride the rest of the day.

Fuentes was a late replacement for scheduled rider Joel Rosario.

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Arms Runner was tended to by track veterinarians and vanned off. Track stewards said the horse trained by Peter Miller was euthanized. Arms Runner had three wins in 13 career starts and earnings of $125,292, according to Equibase.

The video of the race was provided to CBS Los Angeles by videographer Daniel Barcenas. "It just broke our heart right there," he said, "our hearts sank."

Barcenas said he and his family have been coming to the track for years. But after the deadly fall, they did not stick around for the rest of the day's races.

"We don't want to be a part of that anymore," Barcenas said, "It hurts us to see that happen to the horses."

Julie Doran also witnessed the tragedy.

"All of a sudden we saw horses go down," Doran told CBS Los Angeles. "And with what's been going on, it was kinda sad to think. We couldn't even focus on the rest of it. It took a while. And everyone was — especially the kids. They were really upset seeing what was going on."

Arms Runner and Martin Pedroza race in the San Gabriel Stakes at Santa Anita Park on Jan. 5, 2019, in Arcadia, California. AP

Jockey Martin Pedroza, aboard Arms Runner, rode later in the day.

The accident occurred as the horses crossed the dirt surface during the transition from the hillside turf course to the main turf course.

The majority of the fatalities at the Arcadia track since Dec. 26 have occurred on the main dirt surface.

The rest of the nine-race card was completed after the accident.

The track closed March 3 so officials could inspect and renovate the dirt surface after the series of fatalities that have drawn national attention outside the sport and criticism from animal rights groups.

Track officials have not announced a singular cause for the unusual number of deaths.

The Stronach Group, which owns Santa Anita, announced an immediate reduction in the amount of anti-bleeding medication Lasix allowed on race days. The California Horse Racing Board approved the measure and it took effect Friday.

A proposed rule that would eliminate the use of whips, except in cases where a horse's or jockey's safety is involved, still requires the approval of various state agencies.

Meanwhile, CBS Los Angeles reports that animal rights advocates PETA asked Gov. Gavin Newsom to intervene.

"PETA calls on Governor Newsom to urgently form an independent panel to investigate the training and veterinary practices in California racing if the California Horse Racing Board does not take every possible action to protect the horses, then racing should not be allowed to continue."

Races are expected to continue at the track Thursday.