Joanne Boogaard watched her son Derek duke it out on the ice with other NHL tough guys for six seasons as one of the most feared enforcers in the game, a six-foot-seven brawler who was not there to skate or score, but to defend his teammates when it was called for.

"He was there protecting his teammates at all costs," she said in a statement released by her lawyers on Monday, "but who was there to protect him?"

Joanne Boogard and other family members have filed a wrongful-death lawsuit against the NHL, blaming the league for brain damage her son suffered playing the game and for his addiction to prescription painkillers. Derek Boogaard died of an accidental overdose of pain medication and alcohol two years ago; his body was found on May 13, 2011.

The 28-year-old Boogaard was posthumously diagnosed with chronic traumatic encephalopathy, a degenerative brain ailment that can be caused by repeated blows to the head, according to the 55-page lawsuit filed in Cook County (Ill.) Circuit Court late Friday.

One of the attorneys who filed the lawsuit, William Gibbs, said Monday the NHL profited from Boogaard's physical abilities as team doctors dispensed "pain pills like candy" after he suffered repeated injuries.

"The NHL drafted Derek Boogaard because it wanted his massive body to fight in order to enhance ratings, earnings and exposure," Gibbs said. "Then, once he became addicted to these narcotics, the NHL promised his family that it would take care of him. It failed."

NHL deputy commissioner Bill Daly told The Associated Press in an email Sunday night that league has not received the lawsuit and generally does not comment on pending litigation.

But the Chicago law firm of Corboy and Demetrio confirmed in a statement released early Monday that it has filed a wrongful death lawsuit against the NHL, claiming the league "negligently causing the death of Boogaard by supplying him with excessive amounts of painkillers during his career as an 'Enforcer' and failing in its attempt to curb and cure his resulting addiction."

It is the same Chicago law firm that brought a similar case against the National Football League on behalf of the late Dave Duerson, a Chicago Bears player who killed himself in 2011.

Both Duerson and Boogaard were found to be suffering from chronic traumatic encephalopathy (CTE), a brain disease caused, researchers believe, by repeated blows to the head.

Boogaard's body was discovered on May 13, 2011, at his apartment in Minneapolis, Minn. He was adjudged to have died from an accidental overdose of prescription pain killers and alcohol.

Boogaard's family filed a lawsuit against the NHL Players' Association last September, seeking $9.8 million US, but it was dismissed this spring. The family said the union, after expressing interest in helping pursue a case against the league, missed a deadline for filing a grievance. A judge ruled the family waited too long to act and dismissed the case.

'A preventable tragedy'

Gibbs, a lawyer for the Boogaard family, said in the statement that the NHL "needs to adapt and change so that a preventable tragedy like this never happens again, adding that the lawsuit "will unearth the failed policies that have led to the demise of so many NHL fighters and bring to light the need for meaningful change in the NHL so that families, like the Boogaards, can rest easier knowing that their loved ones are safe."

No specific damages have been listed. The jury will be asked to set an amount over the minimum allowed, the Times says. The family would not comment on the suit.

At the time of his death, Boogaard had just completed his first season with the New York Rangers after signing as a free agent. He spent the first several seasons of his career with the Minnesota Wild, who drafted him in 2001.

He only played 22 times with New York, suffering a concussion after a fight in a game in early December. Born in Saskatoon, Boogaard played with Regina, Prince George and Medicine Hat while in the Western Hockey League.

'Family seeks justice'  

Boogaard earned a reputation as arguably the most feared fighter in the NHL. He scored three goals and 16 points in 277 career NHL games and, according to the lawsuit, participated in at least 66 on-ice fights.

In the 2008-2009 season, Boogaard was given 1021 pills by NHL team doctors and dentists, the lawsuit alleges.  And during a two-week period, Boogaard was given 150 pills of oxycodone, taking up to 10 pills per day.

"To deal with the pain, he turned to the team doctors, who dispensed pain pills like candy," Gibbs said in the statement.  "Then, once he became addicted to these narcotics, the NHL promised his family that it would take care of him. 

"It failed. He died. Today, his family seeks justice for the NHL's egregious failures." 

With files from The Associated Press