Late Saturday afternoon, Len and Joanne Boogaard signed paperwork to have their oldest son's brain donated to science.

The generous yet gut-wrenching decision came one day after the shocking news that beloved former Wild enforcer Derek Boogaard, who suffered a season-ending concussion last December with the New York Rangers, died in his Minneapolis apartment. He was 28. The cause of his death is not yet known.

"Derek loved sports and obviously in particular hockey, so we believe Derek would have liked to assist with research on a matter that had affected him later on in his career," said Ryan Boogaard, 27, who along with younger brother Aaron found Derek unconscious and not breathing soon after 6 p.m. Friday.

Boogaard's brain will be donated to the Sports Legacy Institute, who in 2008 teamed with researchers at Boston University Medical School to advance the study, treatment and prevention of the effects of brain trauma in athletes.

In March, it was announced that even though renowned hockey fighter Bob Probert died of heart failure, Probert also had the degenerative brain disease Chronic Traumatic Encephalopathy, the same disease found in 1960s enforcer Reggie Fleming's brain.

CTE is a progressive brain disease believed to be caused by repetitive trauma to the brain, including concussions. Reportedly, 30 of the 40 athlete brains studied have shown signs of CTE.

Boogaard suffered multiple concussions in his career, although the decision by the Boogaards should not lead to a presumption that their son died of complications from brain trauma.

An official cause of death could take at least two weeks as the Hennepin County Medical Examiner's Office waits for results from multiple tests, including a toxicology report.

Boogaard's funeral will be in his hometown of Regina, Saskatchewan, although Ryan Boogaard didn't know a date yet.

Many were overwhelmed by Boogaard's death. Wild fans placed flowers outside Gate 2 of Xcel Energy Center. A Facebook campaign began to hold a Boogaard memorial in the Twin Cities. One mother of a Wild player reached out to several other Wild moms to organize something special for Boogaard's mom, "a lady that we all got to know so well." In a touching moment, the NHL held a moment of silence before Game 1 of the Eastern Conference finals.

"Our family appreciates everybody's calls and condolences," said Ryan Boogaard, who also is grieving in town with his sister, Krysten, and half-brother, Curtis. "Derek loved Minnesota. He loved it here. That's why he made it his place in the summertime. He loved the fans here. He loved playing in that building. He just loved everything about Minneapolis.''

Derek Boogaard was badly affected by his latest concussion. In March, Boogaard said he spent three weeks inside his apartment at one point because of the complications.

"I didn't have people around me," Boogaard said in March. "That's why when [Rangers forward Marian Gaborik] got his concussion, I'd call him every day and say, 'I want you to call me and we'll go for lunch and we'll do something for at least an hour just so you get out of your apartment.' I didn't want him going through the same thing I did."

That was the type of person Boogaard was, former Wild General Manager Doug Risebrough said. "Deep down, Derek had a big heart," he said. "He liked people and he liked to help people."

The New York Post reported Saturday that with two weeks left in the Rangers season, Boogaard left the team to enter the NHL/NHLPA Substance Abuse & Behavioral Health Program. In addition, Star Tribune sources say when Boogaard missed most of the Wild's training camp in 2009 and the first two weeks of the season under the guise of a concussion, he actually was entered into Stage 1 of the program.

Boogaard's path to the NHL wasn't an easy one. He was cut from his junior team in 2002 but drafted by the Wild in 2001, and Risebrough placed Boogaard in Louisiana of the East Coast Hockey League.

"Doug said, 'This guy could be a player,' " former assistant GM Tom Lynn said. "We put him in a really, really challenging skating program because he had the desire and he was tough as nails, and that started the odyssey."

Boogaard was then promoted to Houston of the American Hockey League. With the Aeros, he was coached by Todd McLellan, now the coach of the San Jose Sharks.

"I've had the opportunity to develop a lot of young men, and Derek was a special one," McLellan said. "Nobody ever thought this guy was going to play. Doug Risebrough believed in him, and he made sure that we began to believe in him in Houston.

"... Every time we went to Minnesota, my two little guys would ask me if I saw Boogey. That's the impact he had on them."

Wild owner Craig Leipold said he got a call from his college freshman son, Connor, a former Wild intern, at 1 a.m. Saturday. "You could hear in his voice just how affected he was," Leipold said. "He had a lot of questions, and I had no answers."