DEL MAR, Calif. – Two racehorses died within about an hour’s time Sunday in separate incidents during workouts at the Del Mar Racetrack, track officials said Monday.

Officials from Del Mar Thoroughbred Club said a 3-year-old filly called Needless to Say collapsed about 7 a.m. Sunday after finishing a short workout at the track. The track’s on-site veterinarian determined the horse “likely had suffered a heart attack,” the club said in a news release.

About 50 minutes later, officials said an unraced 2-year-old colt named Arson suffered a serious leg injury after a fall and later was euthanized. At the time of the fall, the horse was working with jockey Geovanni Franco aboard and he was taken to Scripps Memorial Hospital in La Jolla as a precaution, the San Diego Union-Tribune reported.

In a statement, Del Mar CEO Joe Harper said that “we’re devastated” about the loss of the horses.

“Equine and rider safety is our number one priority,” Harper said. “I am out on the track every morning and I see firsthand the love and care these beautiful animals receive and the vets are watching every step they take. We remain committed to continuing to provide the absolute safest racing and training environment in the sport.”

More than 1,900 horses have been stabled at the club for workouts, gallops and jogs since July 12, the club said. They estimate horses have exercised there some 10,000 times without any incidents.

This weekend marked a major milestone at Del Mar as fans were in attendance for the first time since the pandemic hit. Roughly 18,000 tickets were sold for Friday’s opening day and with 2,000 workers also on-site, maxed out the venue’s capacity at 20,000, track officials said.

Racing for Del Mar’s 82nd season continues through Sept. 6.