A new video that shows a nearly 6,000lb killer whale thrashing his SeaWorld trainer for a heart-stopping 15 minutes has been released.The 2006 video was released as part of the on-going litigation against the theme park by the US Secretary of Labor, who alleges SeaWorld has endangered scores of its trainers by exposing them to the dangerous whims of the enormous whales.Kasatka's attack on San Diego trainer Ken Peters eerily foreshadowed the death of trainer Dawn Brancheu in Orlando, who was butchered in February 2010 by another killer whale named Tilikum.The video of the 15-minute ordeal has only now been posted online after it was presented at a Occupational Safety and Health Administration court hearing in September.At the time, Judge Ken Welsch called the video, which was captured by SeaWorld cameras, 'chilling.'In the video, Kasatka grabs her trainer's foot and will not let go, dunking him under the water for extended periods of time.Mr Peters, who remains eerily calm, finally manages to free himself, only to have Kasatka charge him over the barrier net.According to the book Death at SeaWorld, this was the third such time Kasatka attacked, horrifying trainers and audiencegoers alike.'She grabbed his ankles, pulling him underwater for several seconds,' David Kirby writes in the book.'When he resurfaced, she grabbed him again, this time "rag-dolling" her trainer violently by shaking him back and forth with her powerful neck muscles.'He describes her actions as the calculated instincts of a killer.'Then, slowly and deliberately, as if performing a bizarre underwater pas de deux, the whale began to spiral upward with Peters’ foot in her mouth,' he said.'Finally Peters told his colleagues to abandon the recall effort since it only seemed to make Kasatka bite down harder.'Mr Kirby notes that Kasatka was careful to keep Mr Peters in the middle of the pool and away from the other trainers trying to rescue him from the edges.At the time, SeaWorld tried to downplay the incident.'There are times like this. They are killer whales. She did choose to demonstrate her feelings in a way that was unfortunate,' Mike Scarpuzzi, head trainer at SeaWorld, said at the time.Mr Kirby said that Kasatka may have been acting out because she heard her two-year-old calf's cries from another pool.Trainers were eventually able to separate the two with the help of a net, but the whale tried to rip Mr Peters away from safety. His foot broken by the ordeal, rescue personnel were able to save him.'She didn’t show me any precursors. She didn’t tell me, she didn’t show me,' Mr Peters allegedly told the other trainers after he had been rescued.He was rushed to the hospital for surgery and vowed to never swim with her again.This chapter of the sordid behind-the-scenes treatment of trainers and their animals is only the latest disturbing tale out of Mr Kirby's book.Killer whales in captivity have a mortality rate two-and-a-half times higher than those living in the Pacific Northwest, according to figures produced by marine mammal scientist Naomi Rose of the Humane Society.In addition, there are no known records of killer whales attacking humans in the wild, while even mild aggression towards trainers at close quarters is not uncommon.One staff member that Mr Kirby spoke to said he was fired from the park in 1995 for his expressive views on the treatment of the animals.'SeaWorld can make the environment safe, according to them, 98 percent of the times,' said Jeffrey Ventre to ABC's 20/20. 'But what happens when the world's top predator decides to go off behaviour?'Let go from SeaWorld for kissing a killer whale's tongue, a banned action, Ventre said that most staff members violated the so called 'tongue-tacticle' rule and were not fired.Operating in San Antonio, San Diego and Orlando, all SeaWorld's killer whales are called 'Shamus' in honour of the park's original animal and up until the Brancheau incident would perform spectacular acrobatic displays with their human trainer's in enormous pools.Attracting up to 12 million visitors a year across the three locations, SeaWorld was rocked by Ms Brancheau's death after Tilikum dragged her by her ponytail into the water, scalped her and dismembered her.One former trainer, John Jett, told Kirby that trainers were not fully aware of the safety problems related to killer whale work, however one senior trainer told a court investigating Brancheau's death that SeaWorld staff were told they may not survive falling in the water with Tilikum.'A lack of detailed information was the norm whenever accidents happened at other parks,' said Mr Jett. 'I remember one incident when all of us were pulled from water work for a short time. To this day, I don't know what happened.'Now after federal rulings which keep trainers out of the water with killer whales, SeaWorld has a specific emergency procedure should someone fall into the water.