Florida ? Ladies in their spring dresses and men in casual linen suits sipped champagne and nibbled hors d’oeuvres as they waited for the U.S. Open polo match in Wellington. What they ended up with was a field of death.

Magnificent polo ponies, each valued at up to $200,000, stumbled from their trailers and crumpled one by one onto the green grass. Vets ran out and poured water over the feverish, splayed-out animals. But it was no use. One dead horse. Then another. Then more. And within a day, 21 horses were dead.

State veterinarians were still performing necropsies but suspect the horses died from heart failure brought on by some sort of toxic reaction in their bodies. Possibly tainted feed, vitamins or supplements. Maybe a combination of the three.

While polo club officials and several independent veterinarians insisted the deaths appeared to be accidental, it remained a mystery that puzzled and saddened those close to a sport that has long been a passion of Palm Beach County’s ultra-rich.

All the dead horses were from the Venezuelan-owned team Lechuza Polo, a favorite to win the title at what’s described as the World Series of this sport. The team included about 40 thoroughbreds in all, maybe more.