"It was just a gorgeous day," remembered Steve Woolfenden. "It was one of the first really nice days of the spring."
The Wenham, Massachusetts, man and his 3-year-old son, Leo, first-time Boston Marathon spectators, were taking it all in — the energy, the excitement, trying to navigate through the boisterous crowds on Boylston Street to cheer on Leo's mom, Amber, as she crossed the finish line.
But that never happened.
"As I watched the plumb of smoke billow up into the air, it became apparent that this is really abnormal, this is a bomb," Woolfenden said.
Unhurt, but terrified among the panicked crowd, he tried to get his young son to safety.
"My son, Leo, was in a stroller. I went to rotate the stroller and then that's when the second bomb detonated," he said.
Woolfenden was knocked to the ground.
"It felt like just being punched, and then everything went away," he said.
He didn't realize it at the time, but his left leg had been blown off below the knee.
"The first thing I thought of – 'Is my son alive?'" he recalled.
Leo was alive, but bleeding, screaming for his mommy and daddy.
A good Samaritan and a police officer rushed Leo to Boston Children's Hospital.
"I was transferred to Boston Medical," Woolfenden said. "And the entire time, all I could think about was Leo, just thinking, you know, 'I'm probably going to — I could die — I could die and I'll never see him again.'"
His wife, who had just run 25 miles, managed to find her son, and then her husband, in the hospital.
"And she just grabbed my hand and grabbed my head and said, 'Leo's okay, he's alive, he's at Children's,' and, at that moment, I didn't care about anything else," said Woolfenden.
Five years later, Steve and Leo Woolfenden have shown a resilience and strength that has surprised even them. Steve has gotten back into skiing, as part of the Adaptive Sports Program at Spaulding Rehabilitation Hospital — a place where he had spent countless hours and days learning to just walk again on a prosthetic leg.
That prosthesis also hasn't stopped him from mountain biking on the weekends with his friend, Michael Digris.
"Steve's a fantastic mountain bike rider," said Digris. "He's taken a number of falls that definitely would have ended my day, and he shakes them off no sweat."
In fact, Digris has been so inspired by Woolfenden's ability to overcome his disability, he's running the marathon for Spaulding's Adaptive Sports Program with Steve and Leo's number.
"I draw on the fact that there are other people, Steve in particular, who have had to go through infinitely more physical pain than I have," Digris said.
Digris' son, Tom, is also Leo's best friend.
"They have both had to endure things that no kid that age should have to," Digris said.
That's because about five years ago, Digris' family was touched by Spaulding, too. His wife, Michele, turned to Spaulding shortly after giving birth to their second son, as she battled brain cancer that would eventually take her life.
"They got Michele up to speed and well enough where she could come home and be in a hospital bed for enough time when she was still alive to spend time with our two sons," he said.
It's a gift Digris doesn't know if he'll ever be able to repay, but he'll spend 26.2 miles trying, with the Woolfendens' resilient spirit motivating him to cross the finish line.
"Just knowing how much Leo means to my son, Tom, and having Leo's number and running for Leo, and also Steve, is kind of emblematic of everything that their family has done for mine," he said.
Five years later, that finish line taking on new meaning.
"I consider myself really, really fortunate," said Woolfenden. "In a very unlucky situation, I'm a lucky guy."
This year, Spaulding's entire marathon team is raising money for Spaulding's Adaptive Sports Program.