In February 2010, trainer Dawn Brancheau died when the killer whale Tilikum attacked her, dragging her underwater at SeaWorld in San Diego. As the documentary “Blackfish” chillingly uncovers, this was not an isolated incident but a pattern of behavior and one not uncommon to orcas in captivity. In the film, which makes its television debut on CNN on Oct. 24 as part of CNN Film’s Fall Documentary Series, writer-director Gabriela Cowperthwaite interviews former SeaWorld trainers and experts and incorporates evidential footage to tell the tragic story of captive orcas forced to live in close quarters with strangers and perform for humans’ amusement. Cowperthwaite, who spent two years making “Blackfish,” explains what drove her to expose the truth that’s been kept secret for years.

MNN: How did you first hear about the Tilikum story? And what compelled you to make a movie about it?

Gabriela Cowperthwaite: I heard about it on the news, that a trainer was killed. I don’t come from any animal activism. I’m a mom who took her kids to SeaWorld. I’m a documentarian by trade and eternally curious about things — peeling back the onion. I thought it seemed strange. I know that killer whales don’t kill people in the wild. When I started delving into the story, I was shocked by what I learned. I think once you hear what really goes on there with the trainers and the whales, you know that nothing there is what it seems and you feel driven to spread the word, to tell people what they’re really seeing when they go to these parks.

Was it difficult to get the former trainers to speak on camera?

Most of the former SeaWorld trainers had spoken out after Dawn’s death, so they were prepared to speak the truth. They want to spread the truth about what goes on there. They’re leaving the animals they love behind and don’t want to do that without being an advocate and a voice for those animals. There were a couple of people who were not comfortable talking. SeaWorld has a considerable amount of control over people working there. It’s been described as cult-like, everything from the uniform to the PR training where you learn to spin certain facts and learn to cover up things that are happening at the park. It’s a culture of secrecy and quite a bit of truth manipulation. Some people come out of there and still feel like someone’s watching over their shoulder.

Did you try to interview anyone from SeaWorld?
I tried very hard, for six months. We went back and forth and I was encouraged that they were going to speak and I was going to have their voice in the film. I had so many questions I wanted to ask them. At first they were amenable. They wanted to know everything about me. I actually gave them a list of my questions, which you never do because you get scripted answers. But in the end they declined.

Did they try to block the film?
No. They’ve been around for 40 years controlling the message and sidelining any dissent and have been really good at that. I think they saw it as an independent documentary that would just go away.

What did you learn about orcas in the course of making 'Blackfish?'

I knew they were highly intelligent, but I learned they have a part of their brain that we don’t have, they have everything that we have and something that we don’t and can’t even recognize. That blew me away. One of the most surprising things that I learned was what it means to echolocate. When they echolocate they’re essentially delivering a sonogram. It’s a very evolved skill that this animal has. I learned that there’s constant social strife in captivity. They do fight for dominance in the wild but the animal that loses has nowhere to go here. Imagine being confined like that and confronted with conflict on a daily basis. It’s a pretty terrible existence.

OSHA ruled that SeaWorld trainers must be separated from orcas, behind barriers, a ruling that SeaWorld is appealing. Any update?

They’re being represented by Eugene Scalia, son of Supreme Court Justice Scalia. They contend that OSHA has no jurisdiction to rule on this because they don’t understand how whales work.

Have there been any changes or improvements for the whales since the film’s theatrical release?

We heard about things they might be doing to enhance the lives of whales at the park, but it was just a rumor. But their revenue went down 6 percent. I can’t say for sure that it was the film, but it’s been a tough year for SeaWorld. I think that people are starting to pay attention to what’s going on behind the curtain and that can only bode well for the whales.

What do you hope that viewers take away from watching it?

I think it’s very clear that killer whales are not suited to captivity. I think there’s no place for animals in entertainment in our culture anymore. And I think SeaWorld has the financial resources to evolve out of animal entertainment into sea sanctuaries, which are much more dignified and sustainable way of watching whales. People think you can take whales from captivity and throw them back in the ocean, and you can’t do that. They don’t know how to hunt. A lot of them are hopped up on antibiotics so they would probably die or live very short lives. In a sea pen or sea sanctuary, you cordon off part of an ocean cove. There the whales can be killer whales for the first time in their lives. It can be a profit-making endeavor for SeaWorld. But it’s such a drastic business model shift that it would not be a small undertaking. But the bottom line is that’s where the world is moving and if they want to be left behind, so be it. They have the opportunity to be leaders in this. It’s their choice. I hope that people that have never thought twice about marine parks or animals stumble upon this, learn something, and have a perspective shift by being told the truth. I hope that people who tune in will learn something and feel something.

Film shows why captive whales turn killers
Documentary on CNN reveals the shocking truth behind the SeaWorld tragedy.