It has been more than four years since an explosion on the Deepwater Horizon oil platform killed 11 crew members and unleashed 2.4 million gallons of petroleum per day into the Gulf of Mexico, but the effects of the disaster are still being felt. The devastating pollution has impacted the fishing industry and those who rely on it, not to mention the ecosystem. Recovery also eludes the survivors and the families of those who died who are still battling BP, which leased the oil platform, for restitution. Meanwhile, oil drilling continues with more than 3,500 offshore rigs in the Gulf, dozens of newly approved pipelines and no new regulations to prevent history from repeating itself.

Filmmaker Margaret Brown spent the better part of four years interviewing struggling fishermen, Deepwater Horizon survivors, oil industry insiders and others to tell the deeper story of the disaster and its aftermath in her documentary "The Great Invisible," winner of the grand jury prize at the SXSW Film Festival. The film opens on Oct. 29 in New York and Los Angeles, followed by a national release.

"I decided to make a movie that looks at the South through the prism of oil production and consumption. It became so much larger than simply what happened to these people when I started to look at what our collective responsibility really is," says Brown, who previously made "Be Here to Love Me" and the Peabody Award-winning documentary "The Order of Myths." She shared her insights with MNN.

MNN: Why did you want to make this film?

Margaret Brown: A few weeks after the explosion, my dad sent me some pictures of our house in Alabama. The house was surrounded by orange absorbent boom, which was used to keep the oil out of the marsh and off the land. Seeing where I grew up through these pictures was so surreal and felt like some kind of alien invasion. In addition, when I spoke to my family and people I grew up with, there was a feeling of such profound hopelessness. I felt hopeless myself, and thought that making this film was something I could do. 

There have been other documentaries about the Gulf disaster, such as "The Big Fix." What sets yours apart?

There were some documentaries made immediately after the spill. However, I wanted to make a film that was longitudinal; in other words, what happens when the cameras go away? Over the course of four years, I developed relationships with the oyster workers in the Bayou La Batre neighborhood of Hard Luck City, with oil executives in Houston, and with survivors of the Deepwater Horizon explosion.

Why did you take this particular approach? Did you know going in what you were going to do or did it develop as you went along?

It definitely developed as I went along. At first I thought it would only be about what happened just in my community in Alabama. But then I got more interested in how we're all connected to petroleum and the giant factory in the Gulf of Mexico that fuels our lifestyles of convenience.  

What points and messages were important to convey?

I want people to think about what they're doing when they fill up their car everyday. I think the oil industry tries to obscure the link between putting gas in your car and the risk it takes to produce it, but I wanted to bring this relationship to light.

When did you shoot and for how long?

We were on the ground in May 2010 a few weeks after the spill. We shot through the end of 2013.  

What were your greatest challenges?

The main challenge was creative. I wanted to tell both a micro story about emotions and characters but I also wanted to tell a macro story that was about America's complicated relationship with petroleum. I felt it was structurally risky to try to do both in one film, but that was the film I wanted to make.

How hard was it to secure the cooperation of your subjects? Did anyone have to be convinced to participate?

The hardest to convince were with the Deepwater Horizon survivors. Both Doug Jones and Stephen Stone have PTSD from the explosion, and their wives were worried that their participation might exacerbate the situation. We spent hours on the phone and in person talking through how we could do this in a way that was safe for them, but I felt mainly it was really about them feeling comfortable about me as a person, and what I would do with the material. 

Stephen Stone in a scene from the documentary The Great Invisible.

Stephen Stone in a scene from the documentary "The Great Invisible." Stone suffers from PTSD after surviving the explosion on the Deepwater Horizon oil rig.

What impact has the film had so far, and what do you hope it will have with national release?

So far we've only had festival screenings ahead of the Oct. 29 theatrical release, but the reaction has been encouraging. People want to discuss the issues raised in the film and people seem galvanized to action.

What do you want audiences to take away?

People will have their own takeaways based on where they live. Someone living on the Gulf Coast will most likely have a different take than someone living in New York or L.A. However, there are things that everyone can do. On our website, there's a list of things that people can do. For instance, information about whistle-blower protection for workers on rigs, info on how to donate to the Bayou food bank featured in the film, and info on different ways to reduce petroleum consumption.

Is there an update on the lawsuit filed by the Deepwater Horizon survivors?

There was just a $20 billion settlement. However, it's being appealed by BP.

Related on MNN:

'The Great Invisible' explores the environmental and psychological aftermath of the Gulf oil spill
Margaret Brown shares her insights about the Deepwater Horizon spill with MNN.