A year ago, Piper Peterson was achingly close to finishing her fifth Boston Marathon, having just turned right onto Hereford Street, when two homemade bombs stopped the race, sending thousands of runners and spectators fleeing the course.
This year, the 67-year-old from Spokane, Washington is one of 36,000 runners - 9,000 more than last year - and an estimated 1 million spectators coming back to the 26.2-mile (42.2-km) course to wipe away the gruesome memories of last year when three people were killed and more than 260 were hurt.
"I have some unfinished business to complete here," she said before the race on Monday.
Runners and spectators sounded a defiant note on a sunny Monday morning as the 118th race began, vowing to reclaim the event as the joyous family-friendly event it has long been.
Lining up at various checkpoints near the finish line, spectators silently waited for bags to be inspected and cheered loudly as Boston police cruised the course on bikes.
Marsha Quimby, seated at the corner of Boylston and Exeter streets, staked out the same spot where she stood last year just a few feet from the exploding bombs. Despite a fevered rush to leave the route in 2013, she did not hesitate to return and cheer her husband, who is running.
"I feel perfectly safe," she said. "There is a lot of enthusiasm this year and there are a lot of people here now who might not have come otherwise."
One of those is Pam Black, who made her first trip to Boston to cheer her goddaughter near the finish line.
"I feel safer here than in the ballpark in Arlington, Texas," she said with a laugh.
Still, last year's destruction was never far from spectators' memories. At the running store Marathon Sports, where the first bomb exploded, a wreath to commemorate the dead and victims stood in the window with wilted flowers at its base before the race.
Business was brisk. Szilvia Egan, visiting from Dubai, was buying a pair fluorescent yellow New Balance sneakers.
"I've got very good running shoes, but it is Boston. It is sentimental," Egan said.
Down the street at Old South Church, parishioners spent days before the race handing out thousands of hand-knitted scarves in blue and yellow, the marathon's official colors, to give the athletes an "extra dose of love and affection this year," said Marilyn Jackson Adams, who came up with the idea of knitting the scarves in February. They came from 50 states and 11 countries.
At the medical tent where so many victims were treated last year before being shuttled off to hospitals, more than 1,000 medical personnel went through final preparations before the first runners were scheduled to arrive.
Dr. Melissa Kohn, an emergency physician who specializes in race medicine, recalled that last year she was putting an intravenous line into a runner when the bombs exploded. She hoped for less drama this year.
"I would much rather be sitting around being bored than having another disaster," Kohn said.
The horde of specialists, including cardiologists, orthopedic surgeons and psychiatrists, are prepared for whatever happens, she said.
"Everything has been painstakingly planned, and we are ready," Kohn said.
There are more staff and supplies this year, in part because the field of runners is so large, she said.
An emotional call for the city to recover was sounded by many of the racers themselves, including some elite competitors.
Ryan Hall, the fastest American to enter the race, said, "They may have hurt us, they may have knocked us down, but as a result we are stronger and more united."