Here is a round-up of news stories:

(CNN) -- Fourteen thoroughbred horses dropped dead Sunday before a polo match near West Palm Beach, Florida, and a national investigation has been launched to find the cause, officials said.
Teams are trying to figure out what happened at the International Polo Club Palm Beach in Florida.

Teams are trying to figure out what happened at the International Polo Club Palm Beach in Florida.

The South Florida Sun-Sentinel is reporting that as many as 21 horses in total have died between Sunday night and Monday morning.

State and local veterinary teams are trying to figure out what happened at the International Polo Club Palm Beach in Wellington, Florida, as team Lechuza Caracas prepared to compete in a U.S. Open match.

It's unclear what killed the horses but necropsies and blood tests were being done Sunday, the Palm Beach Post reported.

The U.S. Polo Association, the sport's governing body, is expected to open an investigation Monday, the Sun-Sentinel reported.

Two horses initially collapsed, and as vets and team officials scrambled to revive them, five others became dizzy, said Tim O'Connor, spokesman for the polo club.

"A total of seven died on our property," O'Connor told CNN. Seven other horses died as they were transported to a Wellington horse farm and a veterinary hospital.

Vets ran intravenous tubes into the horses, struggling to help them breathe, officials told the Palm Beach Post.

Some horses died immediately, but some lingered for about 45 minutes, according to Dr. Scott Swerdlin of the Palm Beach Equine Clinic, the Sun-Sentinel reported. The clinic is the International Polo's consulting veterinarian group, the newspaper said.

It was unclear Sunday what caused the horses to die, and necropsies and blood tests were underway, said O'Connor. Each team brings between 40 to 60 horses for matches. The ponies are continuously switched out throughout a match to keep them from overexerting themselves, he said.

The horses were between 10 and 11 years old, and were valued at about $100,000 each, O'Connor said, according to the Sun-Sentinel.

A meeting will be held to determine whether Lechuza Caracas will compete at a later date, he said.

"Everybody is kind of in shock and trying to figure out what happened," he said. "Nobody can recall an incident in which this many horses have died at once.

Full story: http://www.cnn.com/2009/US/04/20/dead.horses/index.html

An "isoloated incident" involving one team: www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2009/04/20/national/a001120D42.DTL

"Fans sprayed water mist to cool their bodies." www.miamiherald.com/news/breaking-news/story/1008342.html

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