"Bob lost the fight of his life this afternoon," said Probert's father-in-law, Dan Parkinson, a police officer who performed CPR before Probert was rushed to Ontario's Windsor Regional Medical Center.
Probert was on a boat in Lake St. Clair with his wife, children and in-laws when he "developed severe chest pains" Monday, family friend Rich Rogow told a Monday evening news conference at the medical center.
"This is a tragedy for the family," Parkinson said. "We ask that you respect their privacy at this time."
Probert, who struggled to overcome drinking problems during his time in the NHL, played for the Red Wings in 1985-1994 and for the Blackhawks in 1995-2002.
"Bob was a part of our very first NHL Draft class that also included Steve Yzerman, Joe Kocur, Petr Klima and Stu Grimson," Red Wings owners Mike and Marian Ilitch said in a statement. "Bob was always there for his teammates and was one of the toughest men to ever play in the NHL.
"He also was one of the kindest, most colorful, and beloved players Detroit has ever known."
Blackhawks president John McDonough said the organziation's "thoughts and prayers are with the entire Probert family."
"Bob will always be a member of the Blackhawks family and his memory will live on through our fans," McDonough said in a statement.
The Windsor native had 384 points (163 goals, 221 assists) in 935 career regular-season games with Detroit and Chicago. His 3,300 career penalty minutes rank sixth in NHL history.
"Bob was a guy that started as a strictly tough guy but made himself a player," former Toronto maple Leafs enforcer Wendel Clark told Canadian Press. "Off the ice, everything was a whole different story. He was one of the good guys and he'd do anything for anybody."
Probert was charged several times with driving under the influence while playing for Detroit. He also was caught trying to carry cocaine from Canada into the U.S. in 1989 and served a six-month federal prison sentence.
The Blackhawks honored Probert with a Bob Probert Heritage Night on Feb. 22, 2009, at the United Center, and he dropped the ceremonial puck before Game 3 of the 2009 Western Conference Final between Detroit and Chicago.
No funeral arrangements were immediately made. Probert is survived by his wife and four children.