ARLINGTON HEIGHTS --An animal rights group is calling for the suspension of the jockey who was riding a horse that was euthanized on the track after running the Kentucky Derby Saturday. Eight Belles went down with two broken ankles after finishing second in the race. People for the Ethical Treatment of Animals say the horse was injured before the finish line and jockey Gabriel Saez should not be allowed to race while the horse's death is investigated. Eight Belles' trainer is defending the jockey, saying he handled her properly. The sad end for the derby's second place finisher renews questions about the horse racing industry and how to reduce fatal injuries. Just two years ago, Arlington Park had an unusually high number of catastrophic horse injuries. But track officials took steps to cut down on those injuries. Arlington Park began looking at ways to improve conditions for the horses after a series of incidents in 2006 where some horses were euthanized. The park enters its second season with new safety features. On Friday, Super Miss pulled ahead of the field to win the seventh race at Arlington Park. At 21-1 odds, she was a long shot. As intensely as she raced Friday, she was training Monday morning, which doesn't always happen. Sometimes the horses need more time to recuperate, the park's president attributes quick recoveries to the racetrack's new polytrack. "Times appear to be shorter in duration because of the surface. It is easier for them to work on," said Roy Arnold, Arlington Park president. Last year, Arlington installed polytrack. It's sand, synthetic fibers, recycled rubber and wax. It drains easily, creating a more consistent surface, rain or shine. But more important to trainers, owners and jockeys, the surface is believed to be easier on the horses. "It appears the surface is much gentler for the horses. They come back less sore," said Arnold. Over the weekend, the world watched the Kentucky Derby's exciting finish. Just after the finish, a catastrophic injury took down Eight Belles. She was put down with two broken ankles. It is unclear what led to the injuries. "We hope that the steps we're taking here are going to minimize, not remove, but minimize shows risks and those tragic occurrences in the sport," said Arnold. At Arlington Park, the park's president says their injuries are below the national average and there have been no reports of life-threatening injuries so far this season. On Monday, the Humane Society criticized the industry for running horses too young and breeding for speed, creating fragile horses. Also, PETA calls for horse industry reforms, including all tracks use the synthetic surface. The 2006 derby winner shattered his rear leg at the Preakness that year. The thoroughbred was eventually euthanized eight months later.