ARCADIA, Calif. (FOX 11) - A horse died Thursday morning at Santa Anita Park, bringing the death toll of horses at the race track since last December to 22.
Princess Lili B, a 3-year-old filly, was injured around 8 a.m. during a training session, park officials said.
FOX 11 was in the middle of an interview with trainer Bob Baffert discussing the recent incidents at the track when the injury happened. Baffert said the horse seemed to be "hesitating" a bit and appeared to be "tired" before the animal went down.
Officials later confirmed the horse broke both front legs and that the animal could not be saved.
"We're perplexed by what has happened and devastated," said Tim Ritvo, chief operating officer of The Stronach Group, which owns Santa Anita.
"The track, we have complete confidence in the track, with the greatest track crew in America, and it's just a devastating time for all of us,'' Ritvo added.
Nearly two dozen horses have suffered fatal injuries since the track's winter meet began on Dec. 26.
The race track had been shut down since March 5, when a 21st horse was injured during a workout and died. The park started holding limited training earlier this week, but it remained closed for racing as officials worked to implement a series of new safety protocols.
Santa Anita received 11.5 inches of rain and had unusually cold temperatures in February. However, it was unclear whether track conditions played a role in any of the horse deaths.
The park was also closed for two days in February while the dirt surface was tested. Mick Peterson, a track and safety expert brought in from the University of Kentucky, proclaimed the track "100 percent ready" to resume racing.
Peterson said radar verified that all of the silt, clay and sand, as well as the moisture content, were consistent throughout the track. Its dirt surface was peeled back 5 inches and reapplied.
The highest-profile horse to be euthanized was Battle of Midway, winner of the 2017 Breeders' Cup Dirt Mile. The 5-year-old bay also finished third in the 2017 Kentucky Derby for Hall of Fame trainer Jerry Hollendorfer. The horse suffered injuries during a workout on Feb. 23.
The number of deaths has drawn both concern and criticism. A handful of animal-rights activists gathered outside Santa Anita's main gate last weekend, carrying signs and shouting.
Ritvo said despite Thursday's fatality, the famed track was still scheduled to resume racing on March 22.
"All of these things, the protocols and processes are put in place to prevent this from happening, and unfortunately, sometimes this happens," Ritvo said. "We're going to continue to try and improve those processes, and continue to look at what we're doing, all of us."
Stronach Group Chairman and President Belinda Stronach penned an open letter Thursday afternoon, calling the deaths "beyond heartbreaking" and announcing an unprecedented step of banning race day medication at Santa Anita Park and Golden Gate Fields.
These racetracks will be the first in North America to follow the strict International Federation of Horseracing Authorities (IFHA) standards, according to Stronach, calling it a "watershed moment."
"The Stronach Group has long been a strong advocate for the abolishment of race-day medication, but we will wait no longer for the industry to come together as one to institute these changes," Stronach wrote. "Nor will we wait for the legislation required to undertake this paradigm shift. We are taking a stand and fully recognize just how disruptive this might be."
The mandate encompasses a complete revision of the current medication policy to improve the safety of the horses and human athletes, Stronach said.
The revisions include banning the use of Lasix, legal therapeutic NSAIDS, joint injections, shockwave therapy and anabolic steroids.
Stronach said there will be complete transparency of all veterinary records, an increase in the time required for horses to be on-site before races and out-of-competition testing will also be "significantly increased."
The Stronach Group also planned to invest in diagnostic equipment to aid in the early detection of pre-existing conditions, according to the open letter.
The Associated Press contributed to this report.