It is almost impossible to imagine the trauma at the International Polo Club Palm Beach in Wellington, Florida on Sunday when polo horses started falling to the ground, never to rise again. By the end of Sunday night, 21 elite polo horses were dead.

The horses all belonged to the Lechuza Caracas team and they were being unloaded from their trailers on Sunday afternoon before the start of a match in a prestigious tournament, when, according to reports, two collapsed. The behaviour of the other horses was disorientated and dizzy and then a number of them collapsed on the polo club grounds. Spectators were present, tarpaulins were quickly erected around the horses as vets fought in vain to keep them alive.

Not one horse that was bowled over by the attack, which is being described as “toxic”, survived. It is unimaginably horrific.

It is also, for the moment, inexplicable. The carcasses of over half of the horses were taken to a state agricultural laboratory for necropsies. One question to answer is: how can this have happened in professional sport?

For make no mistake, polo horses of this kind are not far off the most professional of athletes in any sport. They are certainly right up there with elite racehorses. Their value alone is around $100,000 (£68,000) and Lechuza Caracas is so strong a professional outfit that it has teams in the United States, Argentina and the United Kingdom, each team comprising some 40-60 horses and a staff that is around 25 strong.

The key here is the fact that every ounce of each horse’s diet would have been minutely monitored; the point is that food-poisoning on such a scale is virtually impossible. Professionalism in a sport like polo, when it comes at this kind of a level, simply legislates out the possibility of such an occurrence.

To find some context for this, I spoke yesterday to John Horswell, the England polo coach, and he, almost speechless, said there simply was no context. Forget context. There are no minor versions of this, no similar occurrences where the numbers have been smaller.

“Horses die of all sorts of things,” he said. “But absolutely nothing like this. Until there is an explanation, the only reaction is shock and mystification. It is the equivalent of a plane-load of horses flying into the side of a mountain.”

We will leave context there. It serves no purpose to compare one sporting tragedy to another, or equine death to human.

But the point about this disaster is that human expertise has backfired astonishingly. We are so good at professionalism now that we read of sports doctors and the miracles they pull off. Last season, when John Terry recovered from a foot injury two weeks ahead of schedule, his own manager described him as the “bionic man”.

Here, though, the opposite has happened. Whatever the explanation, this is elite sport in a monumentally tragic malfunction.

Playershare anyone?