The 28-year-old player was found dead Friday in his Minneapolis apartment. Few details were available, but the news rippled across the NHL, where the 6-foot-7 Boogaard was a fan favorite and one of the game's most feared fighters. He missed most of last season because of a concussion and shoulder injury from a fight.
"I don't think we have any answers as to what happened or why it happened," Ron Salcer, Boogaard's agent, said Saturday.
Authorities received a report of a man not breathing shortly before 6:15 p.m. Friday, Minneapolis police Sgt. William Palmer said. Minneapolis fire officials were the first to arrive and determined he was dead.
Palmer said authorities do not suspect foul play at this point, but the police department's homicide unit and the Hennepin County Medical Examiner's Office are investigating. Palmer said the medical examiner will decide the cause of death.
An autopsy was being conducted Saturday, but county spokeswoman Carol Allis said results probably will not be released for at least two weeks.
She said in cases with no obvious signs of physical trauma or an obvious immediate cause of death, it takes time to receive results of laboratory tests. Allis said the medical examiner's office doesn't anticipate releasing preliminary autopsy findings until all results are in.
The Minneapolis Star Tribune reported on its website Saturday night that Boogaard's family has agreed to donate his brain to Boston University researchers who are studying brain disease in athletes.
Findings released earlier this year by Boston University revealed that former enforcer Bob Probert suffered from the degenerative brain disease chronic traumatic encephalopathy (CTE). Probert died of a heart attack last July at age 45. Reggie Fleming, a 1960s enforcer who played before helmets became mandatory, also had CTE.
A moment of silence was observed for Boogaard in Boston before the Tampa Bay Lightning beat the Bruins 5-2 in Game 1 of the Eastern Conference finals.
"The news that we have lost someone so young and so strong leaves everyone in the National Hockey League stunned and saddened," NHL Commissioner Gary Bettman said in a statement. "The NHL family sends its deepest condolences to all who knew and loved Derek Boogaard, to those who played and worked with him and to everyone who enjoyed watching him compete."
"It was devastating news," Gaborik said from Slovakia. "I played with Boogey for a long time in Minny and then in New York. He was a great guy. We got along together great. We helped each other out on the ice and off the ice. We were very close. I tried to help him along in New York, and we had a very good relationship. It's just very sad."
"He was one of the very best at what he did. Every team would have loved to have him, whether on the ice or off the ice as a great teammate."
Rangers defenseman Michael Del Zotto said in an e-mail to The Associated Press that Boogaard was "always joking and having fun."
"Anytime anything happened or if you needed anything, Boogey was always there," he said. "He was always a pleasure to be around."
Added Rangers forward Brandon Prust on Twitter: "At a loss for words. I'll miss my roomy Derek Boogaard. You will be missed by everyone. Great friend and teammate."
Prust was still dealing with the shock on Saturday.
"It keeps hitting me off and on all day as I'm driving," Prust said. "Though he was a fighter on the ice, he was definitely a gentle giant off the ice. He was just a real good guy, a team guy all the way. I've been looking at some of the silly pictures I have from when we were roommates and it just hits me what a good guy he was. I still can't believe I am referring to him in the past tense."
Fans, meanwhile, flocked online to express their sadness. For years, fans have been going to YouTube to watch "The Boogeyman" do battle.
His final game was Dec. 9 at Ottawa when he fought Matt Carkner and sustained a concussion and shoulder injury. That was the 70th fight of his NHL career, and by midday Saturday more than 80,000 people had watched replays of that fight on YouTube.
Boogaard signed a four-year, $6.5 million deal with the Rangers in July and appeared in 22 games last season. He had a goal and an assist to go with 45 penalty minutes.
Boogaard was out for the last 52 games of the regular season because of his injuries and did not play in the playoffs. He didn't skate again until about three months after the concussion. He was sent home to Minnesota late in the season to work on conditioning.
Gaborik said he recently spoke to Boogaard, who had his sights set on making a full recovery and having a much better second season with the Rangers.
"We had a lot of good times together," Gaborik said. "He was a really easygoing guy, really caring. We talked pretty much about everything. He's just the type guy who would be there for you whenever you needed him.
"We were in touch a lot. He was focusing on coming back, training every day. He was really looking forward to coming back in great shape and prove that he's the best at what he does. He was really looking forward to that. He was always so positive and optimistic."
In several player polls, Boogaard was voted as the league's most intimidating player. When the Rangers signed him last summer, general manager Glen Sather said the decision was made because Boogaard was "the biggest and toughest."
He had seven fights with the Rangers. His lone goal of the season came at home against Washington on Nov. 9. That ended a drought of 234 games without a goal, dating to Jan. 7, 2006. It was the longest such streak in the league.
Boogaard began his NHL career with Minnesota and appeared in 255 games with the Wild from 2005-10. He missed four games with the Wild because of a concussion. With Minnesota and the Rangers over six seasons, he had three goals and 13 assists and 589 penalty minutes.
"I received a phone call last night at 1:00 a.m. from my son, Connor, who is a freshman in college," Wild owner Craig Leipold said in a statement. "Connor interned for the Wild last year, and his favorite person (not just player) was Derek. You could hear in his voice just how affected he was, since he had just learned of Derek's passing.
"He had a lot of questions, and I had no answers."
That feeling was shared by many, including Minnesota center Pierre-Marc Bouchard, who played with Boogaard for five years.
"Every player on our team felt a little bit more safe with him on the ice with us," Bouchard said in a phone interview. "He was really tough on the ice, but outside the ice he was a great guy."
Wild media relations coordinator Ryan Stanzel first met Boogaard when he was working the ECHL and Boogaard was assigned to Lafayette, La., in 2002.
"I remember the first day he was on the ice, he was larger than life," Stanzel said. "He was so much bigger than everybody in that league. He certainly wasn't the best skater in the world, but he worked 45 minutes to an hour every day after practice with the coaches on his footwork."
San Jose Sharks coach Todd McLellan coached Boogaard for two years in the minors in Houston.
"He was a lovable guy that everybody liked," McLellan said. "Obviously mean and nasty on the ice. He'll be sorely missed."
Born in Saskatoon, Saskatchewan, Boogaard was drafted by Minnesota in 2001 in the seventh round, the 202nd choice. He drew notice in 2007 when he and brother Aaron ran a hockey-fighting class in Saskatchewan. Some voiced concern about such a camp. Boogaard insisted he wasn't teaching kids how to hurt each other, but rather how to protect themselves so they don't get hurt on the ice.
This is the second death of a player in the Rangers organization in the past three years. Alexei Cherepanov, drafted in 2007 but never signed by New York, died at 19 in Chekhov, Russia, in 2008, after collapsing on the bench during a game.
Roman Lyashenko, who briefly played with the Rangers several years ago, was found dead in a hotel in Turkey in 2003. His death was believed to be a suicide.