A killer whale attacked and killed a trainer in front of a horrified audience at a SeaWorld show Wednesday, with witnesses saying the animal involved in two previous deaths dragged the trainer under and thrashed her around violently.

In this photo taken on Dec. 30, 2005, Dawn Brancheau, a whale trainer at SeaWorld Adventure Park, is shown while performing. [Agencies]

Distraught audience members were hustled out of the stadium, and the park was immediately closed.

Veteran trainer Dawn Brancheau, 40, was one of the park's most experienced. It wasn't clear if she drowned or died from the thrashing.

SeaWorld spokesman Fred Jacobs confirmed the whale was Tilikum, one of three orcas blamed for killing a trainer who lost her balance and fell in the pool with them in 1991 at Sealand of the Pacific in Victoria, British Columbia.

Tilikum was also involved in a 1999 death, when the body of a man who had sneaked by Orlando SeaWorld security was found draped over him. The man either jumped, fell or was pulled into the frigid water and died of hypothermia, though he was also bruised and scratched by Tilikum.

A retired couple from Michigan told The Associated Press that Wednesday's killing happened as a noontime show was winding down, with some in the audience staying to watch the animals and trainers.

Eldon Skaggs, 72, said Brancheau was on a platform with the whale and was massaging it. He said the interaction appeared leisurely and informal.

Then, Skaggs said, the whale "pulled her under and started swimming around with her."

Skaggs said an alarm sounded and staff rushed the audience out of the stadium as workers scrambled around with nets.

Skaggs said he heard that during an earlier show the whale was not responding to directions. Others who attended the earlier show said the whale was behaving like an ornery child.

The couple left and didn't find out until later that the trainer had died.

"We were just a little bit stunned," said Skaggs' wife, Sue Nichols, 67.

Another audience member, Victoria Biniak, told WKMG-TV the whale "took off really fast in the tank, and then he came back, shot up in the air, grabbed the trainer by the waist and started thrashing around, and one of her shoes flew off."

But Jim Solomons of the Orlando County Sheriff's Office said Brancheau slipped or fell into the whale's tank, which seemed to contradict Biniak's description.

Authorities provided few immediate details. SeaWorld in San Diego also suspended its killer whale show after Brancheau's death. It is not clear if the killer whale show has been suspended at SeaWorld's San Antonio location, which is closed until the weekend.

According to a profile of Brancheau in the Orlando Sentinel in 2006, she was one of SeaWorld Orlando's leading trainers. It was apparently a trip to SeaWorld at age 9 that made her want to follow that career path.

"I remember walking down the aisle (of Shamu Stadium) and telling my mom, 'This is what I want to do,'" she said in the article.

Brancheau worked her way into a leadership role at Shamu Stadium during her 12-year career with SeaWorld, starting at the Sea Lion & Otter Stadium before spending the past 10 years working with killer whales, the newspaper said.

She also addressed the dangers of the job.

"You can't put yourself in the water unless you trust them and they trust you," Brancheau said.

Steve McCulloch, founder and program manager at the Marine Mammal Research and Conservation Program at Harbor Branch/Florida Atlantic University, said the whale may have been playing, but it is too early to tell.

"I wouldn't jump to conclusions," he said. "These are very large powerful marine mammals. They exhibit this type of behavior in the wild.

"Nobody cares more about the animal than the trainer. It's just hard to fathom that this has happened."

Mike Wald, a spokesman for the Occupational Safety and Health Administration office in Atlanta, said his agency had dispatched an investigator from Tampa.

Wednesday's death was not the first attack on whale trainers at SeaWorld parks.

In November 2006, a trainer was bitten and held underwater several times by a killer whale during a show at SeaWorld's San Diego park.

The trainer, Kenneth Peters, escaped with a broken foot. The 17-foot orca that attacked him was the dominant female of SeaWorld San Diego's seven killer whales. She had attacked Peters two other times, in 1993 and 1999.

In 2004, another whale at the company's San Antonio park tried to hit one of the trainers and attempted to bite him. He also escaped.

In December, a whale drowned a trainer at a Spanish zoo.

Then there was the July 1999 incident at the Orlando SeaWorld, when the body of a naked man was found draped over Tilikum.

Daniel Dukes reportedly made his way past security and remained in the park after it had closed. Wearing only his underwear, he ended up in the frigid water of Tilikum's huge tank.

An autopsy ruled that he died of hypothermia in the 50-degree water. But officials also said it appeared Tilikum bit the man and tore off his swimming trunks, likely believing he was a toy to play with.

Dukes' parents filed a lawsuit against the park later that year but ended up withdrawing it.