Nick Buoniconti, a Pro Football Hall of Fame linebacker and part of the undefeated 1972 Miami Dolphins, died Tuesday night, his family announced. He was 78.

Buoniconti struggled with dementia and was admitted to hospice care this week. He said in 2017 he was convinced that the degenerative brain disease CTE caused by hits to his head while playing football had "taken my life away," and he arranged to donate his brain to science.

"Nick Buoniconti was a true hero of the game," Hall of Fame president and CEO David Baker said Wednesday in a statement. "His inspiring Hall of Fame journey that started as a 13th round draft choice to leading the Dolphins 'No Name' defense is one filled with grit, determination, courage and compassion. Nick's contributions off the field were even greater than what he did on it. He lived a life of honor and nobility and his legacy will live forever through his Bronzed Bust in Canton, Ohio.

"The entire Hall of Fame family mourns Nick's passing and we will keep his wife Lynn and his entire family in our thoughts and prayers."

Born in Springfield, Mass., Buoniconti played at Notre Dame and was drafted by the Boston Patriots of the AFL in 1962. He played seven seasons there before a trade sent him to Miami. So distressed he was by the trade that he planned to retire, The Palm Beach Post reported.

He changed his mind and played with the Dolphins until his retirement in 1976. He was a five-time First-Team All-Pro selection and was named to eight Pro Bowl teams, but was best known as part of the 1972 Dolphins who went 17-0 and are the only undefeated team in the modern era of the NFL.

He had 32 career interceptions.

Years after his retirement in 1976, he recognized the struggles that came with his brain injuries. He was the subject of a 75-minute documentary aired by HBO that showed fans how he struggled to do everyday tasks while still being aware of his diminishing abilities.

Post-career, he had a long career with HBO on its "Inside the NFL" show, and the network remembered him on Wednesday.

"Nick Buoniconti lived an extraordinary life. He accomplished virtually everything he set his sights on in life," the network said in a statement. "He was a trailblazer. Pairing him with Len Dawson on Inside the NFL for 23 years is an unforgettable part of football television history.

"And then having the blessing of Nick and his wife, Lynn, to chronicle his lifelong journey and produce a documentary earlier this year is an important part of our heritage at HBO Sports. It was vintage Nick Buoniconti: honest, raw and to the point. Everybody at HBO Sports is grateful to have had Nick as a friend, colleague and part of our family. We send our condolences to the Buoniconti family."

Post-career, Buoniconti's passion was The Miami Project to Cure Paralysis, which he helped to found after his son, Marc, was paralyzed in a college football game while playing for The Citadel in 1985. The organization is dedicated to raising money and researching spinal cord and brain injuries.

"Today, with a heavy heart and profound sorrow, my family and the entire Miami Project to Cure Paralysis and Buoniconti Fund community mourn the loss of a man who was truly larger than life, my father, NFL Hall of Famer Nick Buoniconti," Marc Buoniconti said in a statement posted to the organization's website.

"My dad has been my hero and represents what I have always aspired to be; a leader, a mentor and a champion. He selflessly gave all to football, to his family and to those who are less fortunate. He made a promise to me that turned into a revolution in paralysis research. We can best honor his dedication and endless commitment by continuing with our work until that promise is fulfilled and a cure is found."