JUDY WOODRUFF: Finally tonight, a close-up look at the NFL’s response to players’ concussions and brain injuries.

That’s the subject of a special two-hour Frontline on PBS tonight called “League of Denial.”

It begins with the story of Mike Webster, who played for the Pittsburgh Steelers in the ’70s and ’80s. He died in 2002 after showing symptoms of brain trauma.

Here’s an excerpt.

NARRATOR: Webster’s Sunday afternoons were spent on the line of scrimmage, brutal territory known as the pit.

MAN: He had the violence in him. He could explode into the player. Every play was a fight.

NARRATOR: Webster’s favorite weapon was his head.

FRED SMERLAS, former National Football League player: Well, Webby would hit you with his head first. And with that head, it would pop you, and then he would lift your shoulders. Now, he’d get it up in the air, once you hit full speed, and you’re moving backwards, and he hits you, you’re gone.

HARRY CARSON, former National Football League player: When he would fire off the ball, he’s coming to block me. And if I’m not ready for him, he’s going to pancake me. He’s going to hurt me.

NARRATOR: Hall of Fame linebacker for the New York Giants Harry Carson went to war with Mike Webster.

HARRY CARSON: And so I have to meet force with force. All of my power is coming from my big rear end and my big thighs into my forearm. And I hit him in the face. I have to stun him, get my hands on him, throw him off when I see where the ball is going.

And when I hit him in the face, his head is going back. He’s going forward, but all of a sudden, his head is going back and his brain is hitting up against the inside of his skull.

MAN: In football, one has to expect that, almost every play of every game and every practice, they’re going to be hitting their heads against each other. That’s the nature of the game. Those things seem to happen around 1,000 to 1,500 times a year. Each time that happens, it’s around 20 g or more. That’s the equivalent of driving a car at 35 miles per hour into a brick wall.

JUDY WOODRUFF: Ray Suarez has more about the Frontline information.

RAY SUAREZ: Mark Fainaru-Wada of ESPN is one of the principal investigative reporters with the documentary, and he’s the co-author of the accompanying book by the same name.

Mark, welcome back to the program.

We just saw Mark (sic) Webster lining up at scrimmage and crashing into other big men over and over again. What happened after his playing days were over?

MARK FAINARU-WADA, ESPN: Well, Ray, essentially, Mike Webster went mad after his career had ended.

You know, he had a life that really — he was a very articulate, smart guy. People thought he would become a broadcaster or a coach. And, in fact, what happened to him was his life sort of fell apart. We detail this extensively in the book and in the film about how he ended up at such a place in which he just — you know, he — lost memory issues.

He was writing thousands of letters that were basically incoherent in many cases. His finances fell apart. And, ultimately, he just didn’t take care of himself in any physical way, his body fell apart, and he died at the age of 50 of a heart attack. And on the death certificate, it also listed post-concussion syndrome was a contributing factor to his death.

RAY SUAREZ: Does he become, in effect, patient zero, the guy who kicks off the inquiries into repetitive brain trauma in the NFL?

MARK FAINARU-WADA: He is patient zero in many ways.

I mean, his case — you know, he ends up at the Allegheny County Coroner’s Office on the slab, and the doctor at the time, the pathologist on hand is a junior neuropathologist named Bennett Omalu, who is a fascinating character in the book and the film, a Nigerian doctor who knows nothing about football, but has been studying neuropathology, who has learned about Mike Webster’s passing and his descent into madness, if you will.

And he decides to study Webster’s brain. And it’s that decision back in 2002 after Webster dies that really sets off the NFL’s concussion crisis, because Omalu discovers in Webster’s brain that he’s been suffering from a neurodegenerative disease that comes to be known as CTE. It’s a disease that was known previously in boxers, but never identified in a football player.

RAY SUAREZ: Well, there have been many cases since Mark (sic) Webster. Has it been medically established beyond a doubt that playing pro football exposes the body to injury that ends in neurological damage and often death?

MARK FAINARU-WADA: It’s a very good question and one that the scientists continue to debate, although I think, you know, it’s fairly well established at this point that you have a number of independent scientists separate from NFL doctors who have been saying for years that there are connections between repetitive brain trauma, repetitive trauma from football and getting — the possibility of getting long-term brain damage.

And for two decades — this is what we lay out in the book and the film — the NFL seemed to blanch at that science and fight back against it and attack those neuroscientists who were telling them that this was an issue that they needed to be dealing with.

RAY SUAREZ: You ask yourself in the documentary, what did the NFL know and when did it know it? How do you answer that?

MARK FAINARU-WADA: Well, I think, as I was saying, you know, it becomes clear that over a period of time beginning in the mid-’90s and up until 2009, you have a heavy layer of denial, that the league begins to hear from at least a dozen, as many as a dozen neuroscientists through surveys, through the study of brains, through commentary this idea that repetitive trauma is connected to long-term brain damage in football players.

And what the league hears — the league hears this, and it has a two-pronged attack. It attacks the scientists who suggest this is a problem, a growing problem. It tries to discourage them, effectively, or rip into them in various ways. And at the same time, they create their own research body, which puts out a series of papers in a neurosurgery journal edited by a consultant to the New York Giants.

And that — those papers basically send a message that concussions are not a problem in the NFL, and that almost NFL players are impervious to these kind of issues.

RAY SUAREZ: Well, in the years since, the NFL has made a massive payment to a class of injured players, changed the rules in practice, taken a look at the equipment, and says it’s trying to deal with this problem. Has it done enough?

MARK FAINARU-WADA: Well, I think that’s the lingering question, clearly.

I mean, one of the things that the experts at Boston University, who are the leading scientists in this, are saying is that the issue with football is not necessarily these big hits that we see all the time shown on highlight, but rather the repetitive nature of playing the game, the blows that has happen, the sub-concussive blows that happen everyday at the line of scrimmage.

And whether you can mitigate those out of the game or not remains to be seen, and whether you would want to, frankly, remains to be seen. It’s a brutal, violent sport, but very popular, obviously. I love it. My brother, who co-authored the book with me, we both love the sport. And, obviously, millions of people love it.

And I think the question is how informed people are in being able to make the decisions moving forward about what they want football to be. 

RAY SUAREZ: “League of Denial.”

Mark Fainaru-Wada, thanks for joining us.

MARK FAINARU-WADA: My pleasure. Thank you for having me.

JUDY WOODRUFF: “Frontline”‘s “League of Denial” airs tonight on most PBS stations.