Medina Spirit, the winner of this year's Kentucky Derby, died of a heart attack following a workout at California's Santa Anita Park, the horse's trainer announced Monday.
The 3-year-old colt collapsed on the track after completing a routine morning workout and died "suddenly," the on-site veterinary team who attended to him determined, according to a statement from Santa Anita Park.
The veterinary team took blood, hair and urine samples from the horse and sent them to the California Horse Racing Board, according to Santa Anita.
A full necropsy, as per protocol in California, will be performed at the University of California-Davis’ School of Veterinary Medicine to try and ascertain the exact cause of this sudden death. The results will be released by the California Horse Racing Board, according to the Park.
Medina Spirit's first-place finish at the Kentucky Derby was dampened by a positive drug test for betamethasone, a joint injection/anti-inflammatory medication, following the race on May 1.
The horse was found to have 21 picograms of the steroid in his system, twice the legal limit. The medication is legal but not on race day in Kentucky, Maryland and New York, the states that host the Triple Crown series.
In June, Churchill Downs suspended Hall of Fame trainer Bob Baffert for two years after the positive test was confirmed.
Baffert maintained his innocence, describing the positive test as a "complete injustice" and maintaining that the steroid was used to treat a skin rash.
A topical ointment, and not an injection, led to the failed test, an attorney for trainer Bob Baffert announced on Friday, The Associated Press reported. The determination was made through urine samples tested by a lab in New York.
The Kentucky Horse Racing Commission will determine whether the test proving the drug was given via ointment and not injection could get Medina Spirit’s positive test tossed out, the AP reported. The investigation is ongoing, according to the commission.
Medina Spirit has not been stripped of his victory. He also came in third in the Preakness Stakes.
Baffert said in a statement, "My entire barn is devastated by this news."
"Medina Spirit was a great champion, a member of our family who was loved by all, and we are deeply mourning his loss," Baffert said. "I will always cherish the proud and personal memories of Medina Spirit and his tremendous spirit."
Baffert also said his "thoughts and prayers" are with Zedan Racing Stables, the owners of Medina Spirit.
"Medina Spirit will be missed by all those who worked with and cared for him," Santa Anita said.
"The Kentucky Horse Racing Commission (KHRC) is saddened to hear of the death of Medina Spirit," the commission said in a statement. "He was a valued member of the thoroughbred industry’s horse racing family."
The California Horse Racing Board is expected to release a statement on Monday.
Santa Anita Park made national headlines in 2019, after dozens of horses died at the racing facility in a single season — the majority on the main track.
The deaths prompted a task force investigation by the Los Angeles County District Attorney’s office and calls from Gov. Gavin Newsrom to shut down after it did not heed the California Horse Racing Board's recommendation to suspend racing when the death toll was at 29.
More than 40 horses died that season.
Despite the highly publicized deaths, the facility boasts a high rate of safety and considers itself the largest training facility in the U.S.
In 2019, horses raced or trained at the facility more than 420,000 times at a safety rate of 99.99%, according to the park.
ABC News' Henderson Hewes, Cheryl Gendron and Bonnie Mclean contributed to this report.