Feb. 25, 2010— -- The casual swing of a ponytail was likely what caused a killer whale in Orlando's SeaWorld to attack and drown an experienced trainer before the terrified eyes of dozens of bystanders, a SeaWorld official said today.
"What we have found out is that Dawn [Brancheau] had just finished up a very good session with this animal. ... She was interacting with him, petting him on the nose," Chuck Tompkins, curator of zoological operations at SeaWorld Orlando, told "Good Morning America." "Dawn had very long hair in a ponytail. That ponytail had swung in front of him. He grabbed her by the hair and pulled her underwater and held her underwater."
Eyewitnesses could see clearly through the viewing glass as the 12,000 pound killer whale named Tillikum thrashed Brancheau viciously underwater.
"We thought it was part of the act," said tourist Wayne Gillespie, who was at the killer whale show with his wife and two children. "We thought maybe they were playing together until we realized he was thrashing around pretty hard. That's how we knew something was wrong."
Within minutes the Shamu Stadium, where the killer whale show takes place, was evacuated. Brancheau was pronounced dead at the scene, Orange County Sheriff's homicide investigators said Wednesday.
Though it's the third time Tillikum has been involved in a person's death, there are reportedly no plans to take the massive animal out of the show.
"We need to evaluate how to do this the right way," Tompkins said. "We need to evaluate our handling procedures and how we interact with him. ... I can guarantee we will make any change necessary.
"He's a good animal," he said.
Brancheau spent 16 years of her life working with killer whales, and Tompkins said she was one of the best.
"We're a small team of people here. We work very closely together," Tompkins said. "It's a huge loss."
Tillikum, a male or bull whale, has lived at the park since 1992, and is one of eight killer whales there.
Dan Brown, vice president and general manager of SeaWorld Orlando, said Brancheau was one of the park's "most experienced trainers."
"It is with great sadness that I report that one of our most experienced animal trainers drowned in an incident with one of our killer whales this afternoon," said Brown Wednesday.
"We have never, in the history of our parks, experienced an incident like this," he said.
"We extend our deepest sympathies to the family and friends and of the trainer and will do everything possible to assist them in this difficult time."
Click here for tips on how to talk to your children about traumatic events.
Tillikum's Previous Attacks
Tillikum has been involved twice before in human deaths.
In 1991, trainer Keltie Lee Byrne fell into a tank holding Tillikum and two other whales at Sealand of the Pacific in Victoria, Canada. A homicide inquest found that the whales had prevented Byrne from climbing out of the tank and ruled her death an accident.
After he was transferred to SeaWorld in Orlando, Tllikum was again connected to the death of a person in 1999.
The body of Daniel Dukes, 27, was found naked, draped across the giant whale's body in July 1999. Dukes reportedly got past security at SeaWorld, remaining in the park after it had closed. Wearing only his underwear, Dukes either jumped, fell or was pulled into the frigid water of Tillikum's huge tank.
An autopsy ruled that he died of hypothermia in the 50-degree water. Dukes' parents filed a lawsuit against the park later that year but later withdrew it.
The Associated Press contributed to this report.
Click here to return to the "Good Morning America" Web site.