ESPN reporters Steve Fainaru and Mark Fainaru-Wada faced formidable challenges when they investigated the National Football League’s denial of the brain injuries suffered by its players. Foremost among them: ESPN has a $15.2 billion dollar contract to broadcast NFL games, so they were investigating one of their own network’s biggest products. Furthermore, the League refused to cooperate with the story and pressured the network to soften its reports. “Every step of the way we got pushback from the NFL,” Steve Fainaru told ProPublica. “They fought almost every story we did.“

The reporting by the Fainaru brothers resulted in “League of Denial,” a book and documentary of the same name by the PBS public affairs program Frontline. The journalists revealed that the NFL spent decades undermining researchers who found links between football and brain injuries, and created their own research arm that downplayed the risks of playing football – even as its retirement fund was paying for brain injuries suffered by players. Behind the scenes, the NFL attacked the project “with a vengeance,” Steve Fainaru said. “They went to our editors, and they went to our editors’ editors. They basically tried to say (the reporting) was wrong without really providing any information.”

The brothers sat down with ProPublica health reporter Marshall Allen on the release date for the book and the documentary, Oct. 8, for ProPublica’s #muckreads podcast. They shared the inside story of how they got the story and the challenges it presented, including the conflict of interest of producing investigative reports that could undermine the profits of their employer and its biggest business partner, the NFL.

Weeks before the documentary aired, ESPN suddenly pulled out of the Frontline partnership, reportedly due to pressure from the NFL. Mark Fainaru-Wada said the breakdown was disappointing, but that ESPN never backed down from their journalism. The brothers are still credited as ESPN reporters in the film. The film uses footage created for ESPN, and the network as promoted their work. “The book and the film are creatures of ESPN – we wouldn’t have been able to do it without the full support of ESPN,” Fainaru-Wada said. “And the one saving grace that Steve and I continue to talk about is that the journalism hasn’t changed a bit. It’s exactly as it was when we went into it.”