Will Jamieson's life lasted just 10 days, but his impact is lasting.
"He was beautiful," his father Scott told WBZ-TV. "Days one through nine, he just looked like this really tiny, cute baby. Just like my other boys. I held him, and I'm glad I got to hold him."
Will was born three months early when a blood clot put both him and his mother, Beth, at risk. Will was transferred to Boston Children's Hospital immediately following his birth.
"Once he was there, I thought [we had made it]," recalls Scott. "He's at Children's and he's going to make it."
But on the tenth day, Will's tiny body couldn't fight any more.
"The end of our Children's Hospital experience was the worst tragedy. The worst thing a parent or person can ever experience," says Scott. "Yet we look at that time so fondly because of the people there. The care he got and the care we got."
The Jamieson's worried about how they'd break the news to Will's brothers. But it almost seemed as though Trevor and Denny were showing their parents how to move on.
"We'd be driving somewhere, and Denny from the back seat will say, 'I'm sad Will died.' So we talked about it," said Scott. "The reaction and honesty and strength they gave back to us … it let us know we're going to be okay."
Jed and Brynn Wartmann are more than just friends with the Jamiesons - they're family. When they were looking for ways to both support the family and honor Will, running the 2018 Boston Marathon with Boston Children's Hospital felt like the right thing to do.
"He just looked at me and said 'I want to run the Marathon. I want to run it with you, and I want to run it for Will,'" recalls Scott. "I'm pretty sure - without hesitation - I said 'yeah, me too.'"
"This was the only way to do it," said Brynn. "As a team."
Running is something Scott says he has never really enjoyed, but it quickly became a sanctuary.
"That's the time that I spend with Will," he says. "I've had my time to process and think and be with him, and that's really special."
And just in time for the Marathon, the Jamieson's have a brand new addition: Calvin Scott Jamieson, born on March 2.
"That was the goal, to get to Marathon Monday and have someone there to watch, in arms, just like his brother will be," says Beth.
Will is going to be with them when friends and family line the course on race day, to cheer on this trio that embodies the heart of every runner's journey.
"The Marathon is a day when Boston is rooting for the human spirit," says Jed.
"Marathon Monday is some of the worst pain people go through, and some of the best," adds Beth. "Kind of like our experience was the worst of the worst, but through it, so much love and support and joy. These three took something hard and made something wonderful."
"We're going to get through this and pick each other up," says Scott. "And love each other, and that's how we're going to get through it. And we have Will - no pun intended."
To contribute to Scott Jamieson's fundraising, visit: http://fundraise.childrenshospital.org/site/TR/BostonMarathon/BostonMarathon?px=1506301&pg=personal&fr_id=1671