BALTIMORE — A horse trained by Bob Baffert was euthanized on the track after injuring a leg during a race on the Preakness undercard Saturday and sending his unseated jockey to the hospital.

Hours before the second leg of the Triple Crown, favorite Havnameltdown buckled forward and threw jockey Luis Saez off his back during the sixth race, and continued running around the final turn in some distress.

The 3-year-old colt was looked at by chief veterinary officer Dr. Dionne Benson and others, who determined the injury to his left front leg was inoperable and decided the horse should be put down, according to a statement from 1/ST Racing, which owns and operates the track.

Saez was conscious and taken to Sinai Hospital for evaluation, complaining of leg pain, track officials announced. He was attended to by medical personnel on the track for several minutes before being put on a stretcher and into an ambulance.

Havnameltdown’s death comes on another major race day, in the aftermath of the Kentucky Derby being overshadowed by seven fatalities at Churchill Downs over a span of 10 days.

“It’s the worst feeling. And we grieve. We do grieve when these things happen. There is nothing worse than coming back and the stall is empty,” Baffert said. “He is a nice horse. He could not have been doing any better. It’s sickening. I am in shock.”

The favorite at 4-5 for the $200,000 dirt race and breaking from the inside No. 1 post, Havnameltdown was bumped out of the gate by No. 2 Ryvit and broke a step slow but continued running in the 6-furlong race. Havnameltdown and Ryvit, the eventual race winner, were out in front of the pack coming around the second turn.

Fans in the crowd at Pimlico Race Course gasped when the horse stumbled before the final turn and tossed Saez. In an incongruous scene, at the same time Saez and Havnameltdown were being looked at, 2Pac’s “California Love” continued blaring from infield speakers set up right near where it happened.

Meanwhile, on Pimlico’s homestretch, the horse was brought under control by track staff, then led behind some black barriers.

“Very unfortunate,” said Tyler Gaffalione, Ryvit’s jockey. “Hopefully, Luis is OK. We were kind of heads-up, and he just kind of disappeared. I looked back and saw Luis coming off the side.”

Baffert pointed out that his horse “was obviously hit pretty hard coming out of the gate.”

“We don’t know if that contributed to the injury, but we will be fully transparent with those reviewing this terrible accident,” he posted on Twitter.

Baffert has horses running on Preakness weekend for the first time in two years after returning from a suspension stemming from 2021 Kentucky Derby winner Medina Spirit’s failed drug test. He was not able to enter horses in the Derby either of the past two years as part of a decision by Churchill Downs. He could not have any in the 2022 Preakness or Belmont because of a 90-day ban in Kentucky respected by Maryland and New York.

One of his horses, Arabian Lion, won an earlier race. Baffert is also set to saddle National Treasure in the Preakness.

Saez, a Panamanian who turned 31 on Friday, originally was supposed to ride top contender First Mission in the Preakness. But that horse was scratched on the advice of veterinarians because of an issue with his left hind ankle.

At the 2019 Kentucky Derby, Saez rode Maximum Security across the line first, but stewards revoked the victory and dropped the colt to 17th for impeding the paths of several horses. Saez then was suspended, accused of causing the interference.

Earlier this year, he was aboard Kentucky Derby champion Mage for a runner-up finish at the Florida Derby. At Churchill Downs two weeks ago, Saez’s horse, Tapit Trice, came in seventh in the Derby.

Havnameltdown, owned by Michael Pegram, Karl Watson and Paul Weitman, had won four of his six career starts prior to this race. He had most recently finished second in the Saudi Derby in February.

“We never had an issue with him,” Baffert said. “We are so careful with all these horses, and it still happens. It is something that is disheartening. I feel so bad for that horse. And I just hope that Luis is OK.”