Hayes, the youngest of five children, was a 19-year-old sophomore at Boston College. He usually drove from dinner back to the house in Dorchester, Massachusetts, with Jennifer, his oldest sister. But when Hayes' father, Kevin Sr., asked Kevin to ride alone with him, he knew something wasn't right.
"We pull up to my house and he starts crying," Kevin said. "I'm like, 'What is going on here?' Either I'm in trouble or he found out something I did in college or something.
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"And then he told me that he had throat cancer."
It was the second time Hayes had to deal with the scourge of cancer. Seven years earlier, his mother, Shelagh, had been diagnosed with colon cancer.
His parents are in remission now, but Hayes and his family still deal with the aftereffects of the disease. And it's why, when the Flyers hold their Hockey Fights Cancer night at Wells Fargo Center against the Vancouver Canucks on Monday (7 p.m. ET; NBCSP+, SNP, NHL.TV), Hayes will wear a special suit to honor his parents.
The lining of his blue suit jacket will have the familiar lavender "I Fight For" signs honoring his parents stitched inside.
"I think it's important that you have stuff like this," Hayes said. "And for me, I can't wait."
Being able to honor his parents this way is something Hayes relishes being able to do. It also allows him to look back on the dark times with a different perspective.
Hayes was 12 when Shelagh became sick. But because of his age and four overprotective siblings -- Jennifer, Eileen, Jimmy and Justine -- Kevin was spared from the worst details.
"I think that was the whole plan anyway, to keep me out of the house," Hayes said. "So the first time I went through it, it didn't seem like it was a big deal. ... I left to go to school (Noble and Greenough, a private school about 10 miles away in Dedham, Massachusetts) at 8 a.m., went to school 8-3, did my after-school stuff, usually went to hockey practice every single night, didn't get home till about 7, 8 at night. My mom always had food on the table for all five of us. So it never really hit me that that it was something serious because I was so active."
It was different when Kevin Sr. got sick.
"It doesn't really hit you until you see the physical changes," Hayes said. "He's all weak, he has no teeth, he lost 75-80 pounds. He's a guy that never missed one of my games ever, from when I was younger through high school, BC. He had the same eight seats every single game and that whole season he wasn't really there. When you get a phone call, every time your mom calls, you're like, 'What's going on?' You expect the worst."
By watching his father fight cancer, Hayes learned more of what his mother had gone through.
"It was funny to talk to her about it because of how badly she was feeling, how much she was battling," he said. "But it just shows how strong of a person she is that she never really let us … there's five of us, five kids, and she never really let it affect anything. I mean, this is a cliché, but she's obviously the rock of our house. For her to go through what she did -- and it's colon cancer, which is a serious thing."
Kevin couldn't visit his dad much in the hospital because of the risk of infection. Visits to his parents' home, nine miles from BC's campus, were also difficult.
"My freshman year my parents would come to my Friday and Saturday games, pick up my laundry, do my laundry and my dad would give me $100," Hayes said. "I was the cool kid on campus. Every Saturday my mom would come pick up my laundry and do it and then she would drop it off. Even on game day, sometimes me and my buddy would drive home to my coffee shop right near my place, stop in and see my parents. It was pretty regular that I went home and saw my parents. And then sophomore and junior year I didn't do it as much. I knew how sick he was, but I don't even think we were allowed to bring a lot of people around him."
Phone calls also were difficult because of the effects of the chemotherapy and radiation on Kevin Sr.
Hayes said the BC hockey community did what it could to rally around him, including coach Jerry York, assistants Greg Brown and Mike Cavanaugh, and teammates Bill Arnold, Johnny Gaudreau and Quinn Smith.
"They knew when to leave me alone and knew when to kind of get my mind off that stuff, whether it's go to the rink or grab some food," he said. "There's a lot going on in my life. I was a sophomore and junior in college and it's supposed to be the best time in your life and I'm dealing with my dad having cancer and playing hockey and trying to make it to the NHL and still trying to talk to my dad."
Despite everything that was going on, Hayes helped Boston College win the 2012 NCAA title with a 4-1 victory against Ferris State in the Frozen Four championship game at Amalie Arena in Tampa. Hayes had an assist in the win.
But his fondest memory came after the game -- his father flew down, against doctor's orders.
"We pull up (to the hotel) after we win, everyone's so happy, and my dad standing there. It was a moment that was unforgettable for me," Hayes said. "Everyone on my team knew what was going on and everyone knows him as 'Big Kev.' ... It was honestly one of the happiest moments I've been in hockey-wise."
Kevin Sr. is 64, Shelagh is 56 and Kevin says each is doing well and enjoying life. Because so many people helped them, and him, Kevin does his best to pay it forward for anyone else going through what he and his parents did.
"I love this month so much," he said. "The hockey community, whether you bring a kid with cancer in or talk to a family that has cancer and you can change their life for 10 minutes, it's so worth it. ... I think that the NHL does an amazing job with this with this Hockey Fights Cancer month, and it's something that I support and something I stand for and something I always will stand for. I'm willing to help no matter what the situation is. And for me, it's not just a month; it's every day."