A killer whale has killed a senior Sea World trainer in the United States, pulling her into the water while visitors looked on.
Police confirmed the trainer was Dawn Brancheau, 40, the Orlando Sentinel reported.
The trainer was grabbed by the waist while she was standing next to the tank and thrashed around in the killer whale tank at Sea World's park in Orlando, Florida, on Wednesday afternoon, a witness told Florida television news channel Local 6.
But Sea World executive Chuck Tompkins said the experienced trainer was pulled into the water by the whale, a five-tonne male orca named Tilikum, the Sentinel reported.
Tilikum means "friend" in the Native American language Chinook.
"It is with great sadness that I report one of our most experienced trainers has drowned in an incident with one of our whales this afternoon," Sea World park manager Dan Brown said.
"We have never in the history of our parks experienced an incident like this and all of our standard operating procedures will be under review.
Sea World had not released the trainer's name but the Sentinel reported Ms Brancheau had been at the park since February 1994.
Witness Victoria Biniak told the station she saw the attack from a public viewing area and also said the whale's name was Tilikum, or Telly for short.
"The trainer was explaining different things about the whale and then the trainer that was down there walked away from the window," Ms Biniak said.
Ms Biniak said the attack was violent enough for Ms Brancheau's shoe to fly off.
Brazilian tourist Joao Lucia De Costa Sobrinho and his girlfriend told the Sentinel they were at an underwater viewing area when they saw a whale with a person in its mouth.
Ms Blancheau was bleeding from the face or mouth and the whale turned her over and over as it swam, Mr Sobrinho said.
A Sea World spokeswoman told CNN the incident did not occur during a performance.
Visitors were evacuated form the area and the whale show was cancelled, but the park was not shut down, the Los Angeles Times reported.
Part-time trainer Keltie Byrne, 20, drowned after slipping into Tilikum's tank at Canadian park Sealand of the Pacific in 1991.
An account of the incident in a Whale and Dolphin Conservation Society book published a year later said Ms Byrne was dragged around the pool, mostly underwater, as Tilikum and two other killer whales played with her.
Tilikum was moved to Sea World following the incident.
"For years, PETA has been calling on Sea World to stop confining ocean going mammals to an area that to them is like the size of a bathtub, and we have also been asking the park to stop forcing the animals to perform silly tricks over and over again," spokesman David Perle said.
"It’s not surprising when these huge, smart animals lash out."
Whale expert Nancy Black told Local 6 that Tilikum could have been playing in the latest attack and did not intend to hurt the trainer.
