Yesterday morning, with pain inevitable and recovery all but impossible, 2006 Kentucky Derby winner Barbaro was euthanized. He had been in intensive care for eight months.

Twenty minutes before the horses were called to the post for last May’s Preakness Stakes, the second act of the Triple Crown races, a friend text-messaged me from an OTB and asked me for my picks. I can’t remember what plays I gave him, but I do remember that I closed with “Barbaro wins Trip C.”

Not only did turf hacks, bettors, and everyone watching the race at the track or on television expected Barbaro to win the race he was about to run, but it was widely felt that he would also win the Belmont Stakes and become not just the Horse of the Year, but the horse of the decade — a Triple Crown winner, breaker of the longest drought in history. This position seemed to need no support, no analysis, and no contingencies. Barbaro had prevailed over a particularly strong field in the Kentucky Derby, and he had done so with such conviction that he made it seem as if he were a horse of a different breed running in a different race. His was the greatest margin of victory in almost 60 years. He was undefeated. He was tractable, powerful, intelligent, and he was very, very fast. This was the real thing. Barbaro was going all the way.

Barbaro didn’t go all the way. He went another few hundred feet. Things looked weird even before the race, when the horse burst through the gate, jumping onto the track in an eager false start. But the horror was yet to come. Running by the grandstand for the first time, the horse bobbled. His head twisted to the left. His right hind leg flailed. Edgar Prado urgently, but gently pulled him up and leapt to the dirt where he assumed the terrible stance of an experienced jockey attempting to act as a fourth leg, supporting a horse with a catastrophic injury and trying to limit the damage and perhaps save the horse’s life. He leaned against Barbaro until the vets came, and then he walked to the side of the track and doubled over in grief.

Usually, a horse with such a severe injury would have been shot on the track behind a screen. Barbaro was ambulanced to the University of Pennsylvania New Bolton Center, tranquilized, and in the morning he received the extensive, thorough, and advanced surgery.

When he woke up from the anesthesia, it was as if one could hear the sigh of relief. The get-well cards arrived, the flowers, the fruit baskets, the well wishes, the Web sites — it all piled up.

When Barbaro developed Laminitis in July, a malady of the hoof, I figured he would not live through the weekend. He made it.

Things looked good, as good as can be expected. The horse was a fighter: Yesterday, he lost.

It’s a difficult thing to say, and I don’t mean to cast aspersions in any direction — everyone involved, Dr. Dean Richardson, owners Gretchen and Roy Jackson, trainer Michael Matz, the many unnamed folks who cared for Barbaro, all of them did a fantastic job, did more than could be expected, and I believe they loved the horse — but was this the right thing?

It wasn’t until August 15 that Barbaro grazed outside. His odds, after the initial surgery, were 50–50.

Barbaro was a high visibility colt, worth an estimated $30 million dollars as a stud. It’s not about money, the owners said, and I believe them. But if one had suggested that every injured horse receive the treatment granted Barbaro, one would be accused of fantastical dreaming. So it is, in a way, about money. Barbaro was clearly worth a lot of it, and money was spent by the handful either for sentiment and affection, or as a long-shot investment for a distant hope of future recoup via breeding. I don’t think either sours the deal. The effort and money spent trying to save Barbaro, who shattered himself for our amusement, was marvelous. But I’m not sure that eight months in intensive care is what’s best for a horse.

It’s a tangled mess to which I don’t think there is a right answer, except perhaps this: Make the sport safer. In 1993, Bill Nack wrote an article in Sports Illustrated and estimated that a horse breaks down — either in racing or training — for every 22 races run. This is a horrible, gruesome number. The totals are in the thousands every year. If this many athletes died playing any other sport that sport would be at least as illegal as cockfighting. Thoroughbred racing is not, at its core, inhumane. It is glorious, thunderous, magical, and romantic. The industry should work hard to keep it so, and in fact, this year a huge movement is under way to replace most of the tracks in the country with a safer, artificial surface.

Make this Barbaro’s legacy. If he couldn’t win the Triple Crown, perhaps he could save the lives of thousands of horses.

Mr. Watman is the author of “Race Day: A Spot on the Rail With Max Watman.”