LOUISVILLE, Ky. - For the second time in six months, tragedy struck one of thoroughbred racing’s showcase events. The arrival of a new racing surface, however, could usher in an era of safer American tracks.

Pine Island was fatally injured and Fleet Indian hurt Saturday in the $2 million Breeders’ Cup Distaff at Churchill Downs.

The injuries caused a collective wince in an industry already struggling to attract a younger generation of fans. The latest accidents, coupled with Barbaro’s life-threatening injury in the Preakness in May, did not help.

“None of us want to see what happened yesterday,” trainer Doug O’Neill said Sunday. “People who don’t know the business don’t know how much loving and care these horses get. If you only see tragedy, you might get a bad image (of the sport).”

Pine Island, the 3-1 second choice, fell on the backstretch, sustained multiple fractures and had to be put down. Fleet Indian, the 2-1 favorite trained by Todd Pletcher, was pulled up with ligament damage and is expected to recover.

Jockey Javier Castellano was pitched over the top of Pine Island as the 3-year-old filly fell, but he wasn’t injured and returned about an hour later to ride Bernardini to a second-place finish in the Classic.

“She was running good. We got on the backside, and I asked her to switch leads, and it happened so fast,” Castellano said. “She broke down. I don’t know what else to say.”

Announcer Trevor Denman never mentioned Pine Island’s breakdown in his race call, although he noted Fleet Indian was eased approaching the finish line.

“These horses receive extraordinary care and training,” said Greg Avioli, president of Breeders’ Cup Ltd. “There have been advances in veterinary medicine over the years that allow the doctors to do so much more to save them. Barbaro is a great example of that.”

Barbaro, winner of the Kentucky Derby, is expected to have the cast on the right hind leg he shattered in the Preakness removed this week.

Reducing racing injuries is one of the top issues facing the industry.

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A new Polytrack surface — composed of sand, synthetic fibers, recycled rubber and a state-of-the-art drainage system — was installed at Keeneland in time for its fall meet last month. During 16 days of racing, there was only one breakdown compared with seven during the same span in 2005.

There was a dramatic reduction in breakdowns at Turfway Park in Florence, which already has gone through a year of racing on the surface. There were three catastrophic accidents in which horses had to be euthanized; there were 24 in 2004.

The primary advantages to artificial tracks are easy drainage, allowing for races in practically any weather, and safety, with a more even composition across the track.

California’s Hollywood Park is the latest track to change from dirt to an artificial surface. Its autumn meeting began last week, and breakdown statistics are not yet available.

O’Neill, who is based in Southern California, is enthused about the new surface, which has attracted some East Coast trainers like Pletcher to relocate to Hollywood Park for the winter.

Artificial surfaces will be mandatory at California’s other major thoroughbred tracks — Santa Anita, Del Mar, Los Alamitos, Bay Meadows and Golden Gate — by Jan. 1, 2008.

But O’Neill doubts a tradition-heavy track like Churchill Downs will run the Kentucky Derby on anything but dirt in the near future.

Hall of Fame trainer D. Wayne Lukas disagreed, saying, “I’d take odds we’ll have it here in three years. We need it everywhere.”

The Breeders’ Cup has been the scene of some tragic accidents in its 23-year history.

Pine Island’s fatality was reminiscent of Go for Wand’s gruesome breakdown in the 1990 Distaff at Belmont Park.

Go For Wand snapped her right front ankle and tossed jockey Randy Romero toward the outside rail. Before a stunned crowd, Go For Wand got up and hobbled on three legs, with the mangled part of her fourth limb dangling grotesquely before she collapsed. She was euthanized in front of the grandstand.

That year, Shaker Knit fell over Mr. Nickerson racing into the turn in the Sprint, bringing down both horses.

In the ’94 Juvenile Fillies, Flanders won, but pulled up lame and was retired.