PALM BEACH, FL – Twenty-one thoroughbred horses mysteriously died before a polo match on Sunday. What was the cause?

Officials are currently waiting on test results to find out why twenty-one horses from a Venezuelan team quickly fell ill and died before a match in a Florida polo tournament.

The team Lechuza Caracas were unloading at the International Polo Club Palm Beach in Wellington, Florida, for a US Open match when two horses collapsed. As vets rushed to revive the two, another five became dizzy and soon keeled over.

Intravenous tubes were used to help the horses breathe, but ultimately seven died on the scene. Some were immediate, others lingered for up to 45 minutes. Another seven died on the way to off-site medical care, and the last seven went overnight.

Although nothing is conclusive yet, veterinarians believe some kind of poison caused the heart failure. But how did the horses receive it? “It could be the water, hay, bedding. We just don’t know. When we find out what it is, we will take all the necessary actions,” said John A. Wash, the polo club’s president of club operations.

Dr. James Belden said it remains to be seen “whether it’s something in the environment or something that the horses were exposed to.” He said the routine in the horses’ stable ahead of the match was absolutely normal, leading many to wonder if it was in fact sabotage.

Each horse was valued at $100,000, bringing the loss to over $2,000,000 for the Lechuza Caracas team.