Why did this happen? I found the answer thirty years ago when I was producing a film for Hollywood Park, California. This is a racetrack where a high number of horses meet the same, broken-leg fate every racing season.

At the same time I was also producing a film about vacationing in a motor home, and I filmed a horse whisperer. In thirty minutes he saddled and rode a never-before-ridden-wild mustang from Montana. I talked with him about the racehorse, broken-leg problem and he explained it this way. "A horse has what is called a frog in his hoof, which is a highly sophisticated radar device. As a horse's lead hoof reaches out for the ground, it wobbles back and forth and tells the leg which way to brace itself."

I verified the whisperer's statement with close-up movies of racehorses' lower legs and hoofs; the movies were taken at 1,000 frames per second. This slows down the action so that it takes almost forty times as long to see the action. Sure enough, the hoof does wobble as it reaches for the ground. But when a hoof gets plugged up with dirt, it cannot sense where the ground is because the frog/radar has lost its sensitivity. This fact, together with the fact that thoroughbred’s ankles are not a lot larger then a human’s wrist, makes for potential trouble.

After talking with the horse whisperer, I asked Charlie Whittingham, one of America’s leading horse trainers at the time, about the broken legs. He said: "Sometimes I will take a screw driver and pry the compressed dirt out of the hoof, put it in a bucket of water and it won’t dissolve in a week! It is really solid dirt."

When I started to do some sound recording back at the racetrack, it was impossible because incoming jet airplanes would fly overhead to land at LAX about every sixty seconds. My conclusion was that the kerosene from the airplane exhausts floated down on the carefully prepared, dirt racetrack, and the dirt/kerosene mixture really made the dirt end up solidly cemented into the frog of the horses' hoofs. The caked dirt was the cause of many of the leg injuries.

When I went to the management of Hollywood Park with my theory, I was told, "We hired you to make a movie, not to tell us how to run our race track."

The finished film on the racetrack received more worldwide recognition than any ski film I ever produced. It even won a silver, Olympic medal in an Italian film festival.

Did the film save any more thoroughbred racehorses from breaking a leg because of plugged hoofs? No.

Some people might say that as the filly, Eight Belles, made her way around the turn after the finish line of the 2008 Kentucky Derby she stumbled on the holes in the dirt from the twenty horses that had just run around the track a few minutes earlier. I don’t think so. My guess is that the frogs in her front hoofs were full of compressed dirt.

Is there a chance that what I have to say about racehorses will be recognized by the thoroughbred community? Probably not. However, it has been a recurrent nightmare of mine seeing (along with millions of other television viewers) the filly, Eight Belles, lying in the dirt.

The horse racing community has never come up with some method of keeping dirt from compacting and thus making the frog in the hoof incapable of figuring out where the ground is, and on what angle. Perhaps there is some kind of dirt lubricant or a new hoof design that would keep dirt from compacting in the hoof. After all, a cowpony (not a racehorse) can run down a rock-strewn hillside, across a stream with two feet of water that is full of odd shaped rocks, up the other side, and not break its leg. But it doesn't run and walk in prepared dirt.

Editor’s Note: This is one in a Tahoetopia series written by Warren Miller, legendary ski cinematographer. For other columns by Warren, click on Warren Miller.