TORONTO -- There was a smile on Brendan Shanahan's face and an ache in his gut as he walked out of the Toronto Maple Leafs dressing room Monday.

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His Maple Leafs had just defeated the Boston Bruins 3-1 in Game 6 of the Eastern Conference First Round, evening the best-of-7 series 3-3 and setting up Game 7 in Boston on Wednesday (7:30 p.m. ET; NBCSN, CBC, SN, TVAS, NESN).

But the euphoria of the victory being enjoyed by the Maple Leafs president and the cheering fans who were leaving Air Canada Centre was tempered by the tragic event that had stunned Toronto earlier in the day.

At about 1:30 p.m. ET, approximately 12 miles north of the arena, a man driving a van veered onto a crowded sidewalk and plowed into pedestrians, leaving 10 dead and 15 injured as of 11:30 p.m. ET.

Shanahan was born in Toronto. He grew up here. And like so many Torontonians, he was in shock.

As he was driving in for Game 6, he asked himself if playing the game was the right thing to do for the city he so loved, a city in mourning.

Would it be wrong to play the game, he asked himself.

"You know what? It would have been more wrong not to play it," Shanahan said. "It doesn't make up for it. And I don't think it makes any of us feel any better. It was so emotional. I thought about it all day long. It was sort of really difficult to focus on the game. I honestly don't know if I can properly articulate how I feel about it. The sadness, yes, but also the anger I feel."

Video: BOS@TOR, Gm6: Toronto holds moment of silence

Shanahan paused. He was having trouble finding the right words. On this tragic day, he wasn't alone.

"I think in times like this, you do what you do," Shanahan said. "You do what your city does. And you don't change what your city does. And it doesn't mean you don't honor the victims. And it doesn't mean you're not all thinking about them.

"But as hard as it is, you do what your city wants to do."

What a city in mourning wanted was for its beloved Maple Leafs to provide a distraction from the events earlier in the day.

And win, of course.

The Maple Leafs did both.

As fans arrived for the game, there was extra security everywhere you looked. Streets around Air Canada Centre were cordoned off. Police cars and dump trucks blocked arteries leading to Maple Leaf Square, where several thousand fans were not going to let fear keep them from watching Game 6 on the giant screen attached to the outside of the arena.

And on a day of so many tears, their Maple Leafs elicited loud cheers.

With warmups about to start, Bruins center Patrice Bergeron was interviewed on "Hockey Night in Canada." Five years earlier, Bergeron experienced similar heartache while his city mourned the attack at the Boston Marathon on April 15, 2013. Three people were killed and more than 260 injured.

"I can guarantee you the city of Boston is with the city of Toronto," he said.

There was a moment of silence before the opening puck drop. Moments later, the capacity crowd of 19,604 sang "O Canada" with a verve and vigor that exceeded anything we've heard at Air Canada Centre this season.

The boisterous crowd finally was silenced when Bruins forward Jake DeBrusk beat screened Maple Leafs goalie Frederik Andersen 62 seconds into the second period to give the visitors a 1-0 lead.

The roar was soon restored, however, when Maple Leafs forward William Nylander scored on a fat rebound past Bruins goalie Tuukka Rask just 35 seconds after the DeBrusk goal to tie the game 1-1.

Cue the heroics of Maple Leafs forward Mitchell Marner.

At 13:25 of the second period, Marner pounced on a loose puck in the high slot, wheeled around in one motion, and scooped a backhand past Rask to give the Maple Leafs a 2-1 lead. The volume of the ensuing cheers made your ears ring.

Video: BOS@TOR, Gm6: Marner on Leafs' Game 6 victory

The only time the decibel level in the building was louder than that was at 18:46 of the third period when Tomas Plekanec scored into an empty net to complete the 3-1 victory.

Marner is a Toronto-area kid. He spent part of his childhood in Thornhill, about four miles north of where the van attack happened.

How fitting that a local kid helped his city heal.

"It's happening too often now, these things," Marner, 20, said. "It [stinks]. This world's made for loving each other, make each other better."

Marner was named First Star. He's been the Maple Leafs' best player in this series with six points (two goals, four assists).

"This is a big win for us after an emotional day," he said. "A very emotional day."

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Maple Leafs forward Zach Hyman, a Toronto native, was stunned by the attack.

"You see things like this on CNN happen in other cities, but you never imagine it would happen here," he said. "Never here. And then it does. And then you're in shock.

"Hopefully, we could cheer up people just a little bit."

Coach Mike Babcock said he didn't need to talk to his players about what had happened. Each one was aware.

"We're fortunate to live in such a fantastic city with great first responders and the work they've done," Babcock said. "It's so important we rally around these people, help out and do everything we can.

"We have a fantastic city, and we can't let this get in the way of what we've got going."

The Maple Leafs will try to keep their Stanley Cup hopes going in Boston on Wednesday.

In the process, they'll be helping their city deal with its grief.

Video: Maple Leafs beat Bruins at home to force Game 7