When the first filly to run in the Kentucky Derby in nearly a decade shockingly broke two ankles and was euthanized shortly after taking second place in Saturday's race, it reignited the debate of whether horse racing is too cruel and dangerous for the animals.
Injuries like Eight Belles' aren't uncommon in an industry in which thoroughbreds can run 45 mph at full speed. Every year, hundreds of horses collapse on America's racing tracks after leaving the starting gate, and many of them die.
By some estimates, two horses face career-ending injuries on the race track every day, and there have been on average 1.5 deaths for every 1,000 starts in American racing, according to various studies conducted at 10 American racecourses over the past few seasons.
The races can be taxing on the animals' delicate bodies. A 1,000-pound horse will place the equivalent of 100 times the force of gravity on each hoof with very stride.
"It is a freak accident, but these accidents keep happening on national television in the biggest races to some of the biggest stars of the sport, and because of that racing has a big problem," said Louisville Courier-Journal writer Eric Crawford.
Eight Belles' death came just two years after 2006 Derby winner Barbaro, who was seen as a Triple Crown contender, crashed through the starting gates and shattered his rear leg at the Preakness in May 2006.
Despite months of therapy and efforts to rehabilitate the horse, the thoroughbred couldn't overcome the injuries and was euthanized in January 2007.
"The gene pool is not as strong as it used to be, and I think that is a big reason why you are going to get injuries," said horse trainer Nick Zito, who has been in the business for 35 years.
But some say the injuries have less to do with gene pools and more to do with the surfaces on which the horses race. Like most tracks in the nation, Churchill Downs' is hard-packed mud, but it's now looking into a synthetic surface called Polytrack. Polytrack is made up of recycled rubber, carpet fibers and silica sand, which is coated in wax.
Advocates say the synthetic surface is easier on horses' legs because it softens the impact on the hooves and has led to decreased injuries.
"[It is] more forgiving on horse's skeletal system," said ESPN horse racing reporter Jeannine Edwards.
Several tracks in England have used Polytrack for years. Turfway Park, in Florence, Ky., already it installed, and Keeneland in Lexington, Ky., has Polytrack surface on its practice course.
Following Barbaro's death, the California Senate passed a bill that compelled major horse tracks in the state to install Polytrack or something similar.
Yet the potential for softer tracks isn't enough to convince some critics that racing is safe for the animals. People for the Ethical Treatment of Animals has called for an investigation into jockey Gabriel Saez to determine whether Eight Belles was actually injured before the race began.
Former horse trainer Edwards said that was highly unlikely.
If Eight Belles had had a fracture at the beginning of the race, then the leg would not have held up as long as it did and would have broken down long before the finish line, she said.
Edwards said the industry does need to clean up and ban steroids, which some trainers use to bulk up their horses. But "I don't think you can blame that on what happened. It was a freak occurrence," he said.