Family members of Dave Duerson, a former Chicago Bears player, filed a wrongful death lawsuit against the NFL. Duerson played safety for the Bears in the 1980s, including the Bears Super Bowl-winning season. He committed suicide last year.

Now his family is suing because they say Duerson was depressed, caused by head trauma suffered during his professional football career.

“If the NFL did something for Dave Duerson during his retirement rather than provide him with false information, he likely would not have committed suicide,” said William T. Gibbs, an attorney representing Duerson’s family.

The lawsuit alleges the NFL knew about the harmful effects of poorly managed concussions.

“The NFL sets up a committee to say there’s no way that there could be later in life cognitive or mental health issues as a result of repetitive head trauma in the face of hundreds of articles saying exactly the opposite,” said Gibbs.

Attorneys said that during Duerson’s 11-year career in the NFL he sustained at least three documented concussive brain traumas and numerous unreported concussions.

Researchers at Boston University determined from postmortem analysis of Duerson’s brain that he suffered from Chronic Traumatic Encephalopathy (CTE). CTE is a degenerative brain disease linked to repeated brain trauma.

The NFL said in a statement it hasn’t yet seen the lawsuit. Riddell Sports Group is also named in the lawsuit, which claims the company failed to warn that its helmets would not prevent concussion-caused CTE.