It happened during a program at Discovery Cove in Orlando where people get to swim with dolphins, rays and tropical fish.
Two dolphins swam into the deeper center of a lagoon and then leapt from the water. They collided and a 30-year-old dolphin named Sharky died. The other dolphin appears to be OK.
A park spokeswoman calls it "a very unfortunate and very rare incident."
It's the first accidental death of a dolphin at the park since it opened eight years ago.
About 32 people were gathered along the perimeter of the lagoon about 50 feet away in hip-deep water when the dolphins collided.
