Steve Montador had died on Feb. 15 at the age of 35. The former NHL defenseman was unconscious in his home in Mississauga, Ontario. According to the authorities, a 911 call was received after 2 a.m. on Sunday. But upon arrival, attempts to revive the athlete were unsuccessful.

Steve Montador's cause of death has not been released but foul play is not suspected. According to USA Today, an autopsy will be conducted while the family asked for privacy as they deal with the shocking news.

"Emergency services arrived and attempted CPR with negative results," Peel Regional Regional Police spokeswoman Fiona Thivierge said, Toronto Sun quoted. "Foul play is not suspected, pending the outcome of an autopsy. We are not treating it as anything criminal. It's a sudden death, so there's nothing to indicate anything untoward. It's deemed to be of natural causes."

Steve Montador was a Canadian professional ice hockey defenseman. In 571 NHL games, Bleacher Report revealed he had scored 33 goals and had 98 assists. He last played in the 2011-12 season of the NHL for Chicago Blackhawks. Throughout his 14-year and 10-season NHL career, he had played for six franchises including Calgary Flames, Florida Panthers, Buffalo Sabres, Anaheim Ducks, Boston Bruins and Chicago Blackhawks, Yahoo! Sports reported.

Steve Montador, who's an expectant father in a few weeks, was part of the group of players in the NHL Players' Association who were suing the NHL over concussions, TSN reported. He was plagued by concussions throughout his hockey career. And after last playing in the NHL, The Daily Mail learned he openly spoke about his injury and subsequent depression.

"This injury reminded me of how important it is to think of your health in the long term, and not just for the time being. I've been in this situation before, so I've tasted it all," Montador said, as quoted by Washington Post. "I know people talk about sports being a microcosm for life, and it's very true that way. I can see why people have a hard time with ... being taken away from something they love to do."

"There's a lot of uncertainty, a lot of fear, a lot of anxiety and depression," he added. "I've had a lot of help to work through that, and I feel like I've taken the right steps."

Meanwhile, messages of condolences flooded on social media as fans and friends expressed their sadness over Steve Montador's sudden death.