When runners' feet failed, hands and heart prevailed.
Zach Prescott showed the kind of teamwork that's become commonplace in the final leg, helping to carry a fellow marathoner the last half-mile "and plopped him across the finish line," he said.
"I went out for a personal goal and that went out the window, so the last four miles became enjoying it and helping people out," he explained.
The crowds at Marathon Monday are some of the best in sports. Among them was Alex Gornick's family, stationed atop Heartbreak Hill, each carrying a different cutout of his face making a silly expression.
They'd been out to support him in the past, too — they this is his fourth, Boston Marathon, they said, adding that they expected him to cross the finish line in about 3-and-a-half hours despite carrying a niggling injury.
Also leaning on the support of her family was former champion Desiree Linden, whose father attended for the first time in years since being diagnosed with Parkinson's disease.
"I think there's always tough moments and you think about the people that are watching you and who are expecting you," she said, adding that her parents told her she "did an awesome job."