The evils of SeaWorld and other marine parks are explored in a brand new documentary, "Blackfish," detailing the abuse of orca whales and subsequent trainer deaths, including the three horrific trainer killings by traumatized orca Tilikum, which opens today in Los Angeles and New York.

Veteran SeaWorld trainer Dawn Brancheau's death during an orca show was initially blamed on her slipping and falling, though SeaWorld officials later claimed that 12,000-pound captive whale Tilikum was attracted to her ponytail, resulting in him grabbing and playing with it. But the truth about what happened is far more disturbing, the Seattle Times reports.

"Shamu Stadium always seemed kind of garish and unsettling, but I went with the flow. I would see hundreds of people laughing and smiling and I'd think, 'Could something that makes everyone this happy be that bad?'" filmmaker Gabriela Cowperthwaite told the Sarasota Herald-Tribune.

"Tilikum did not attack Dawn," SeaWorld said in a written response to the film. "All evidence indicates that Tilikum became interested in the novelty of Dawn's ponytail in his environment and, as a result, he grabbed it and pulled her into the water."

However, "Blackfish" aims to prove otherwise, arguing that Tilikum aggressively dragged Brancheau around the tank during a show, scalping and killing her in front of tons of horrified tourists.

Key footage from the tragic incident became public following the Occupational Safety and Health Administration taking SeaWorld to court, shocking new images becoming exhibits in the case.

It took director Gabriela Cowperthwaite years to uncover all of the footage used in her new film, which she painstakingly obtained through local and national newscasts and people's personal archives under the Freedom of Information Act.

"It was just perseverance when it came to getting footage," Cowperthwaite said in an interview. "I couldn't believe what I was seeing. Once you see that, you can't unsee it. In my mind, that gave me my directive. Now that I know the truth, I have to tell the truth. I didn't imagine that I was going to be making this film. I thought I was gonna be making a completely different film about relationships with our animal counterparts. So it was really learning through interviews and stuff and seeing footage."

So if Tilikum really did attack his trainer, what caused him to do so? And why?

Tilikum was born in the wild near Iceland in 1983. He was soon captured and sent to a marine park near Vancouver before being sold to SeaWorld in Orlando. In "Blackfish," disturbing footage shows divers trapping and kidnapping baby whales to be sold while their mothers looked on helplessly, screeching in agony.

After being forcibly separated from his family, Tilikum was kept in a small, dark tank with no lights for up to 14 hours a day, and was allegedly bullied by other calves. Under these conditions, "Blackfish" argues that Tilikum became psychologically traumatized, resulting in his inclination to go into a "whale psychosis" and kill three of his trainers later in life.

The film also points out that there are no records of killer whales attacking humans while in the wild, arguing that wild animals being captured for entertainment can have deadly consequences.

Click here to see photos of Tilikum from his time at SeaWorld and interacting with one the trainers the film claims he killed, as well a photo of the film's director.