Four years after the Boston Marathon bombings, the father of 8-year-old Martin Richard placed a large wreath on the Boylston Street sidewalk where the second of two bomb blasts killed his youngest son.
Draped over the white and yellow flowers was a white ribbon bearing the date “April 15, 2013.”
Two Saturday morning wreath-laying ceremonies at the sites of the blasts — the first at 671 Boylston St. and the second at 755 Boylston St. — marked the start of One Boston Day’s commemorative events.
Bill Richard stood in silence at the second site with his wife, Denise; daughter, Jane; and oldest son, Henry, as bagpipes played “Amazing Grace.” He briefly hugged a relative of Lingzi Lu, a 23-year-old Boston University graduate student from China who was also killed in the second blast, as the families gazed at the wreaths.
About 210 yards away, the family of 29-year-old Krystle Campbell placed a similar wreath at the spot where the first blast killed the Medford native.
People who were wounded in the Marathon bombings, along with Mayor Martin J. Walsh and Governor Charlie Baker, were present for the commemoration.
Marathon bombing victim Heather Abbott, who lost her left leg below the knee in the second blast, said One Boston Day is about “making some sense out of something senseless.”
“It certainly brings you back to four years ago,” Abbott said. “We’re trying to make it a good day and celebrate some of the successes and good things that happened out of the tragedy.”
At 2:49 p.m. — the minute the bombs exploded — the city observed a moment of silence.
Social media lit up as the crowd of hundreds gathered at the Marathon finish line became still. At Fenway Park, players paused batting practice and fans rose from their seats in the stands.
And in Dorchester’s Peabody Square, Baker and Walsh joined the Richard family to mark the moment. Church bells rang while scores of the family’s neighbors and friends stood beside them.
Walsh tweeted, “To the Richard family: you are truly special people. We’re here to say we support you, we love you, and thank you. #OneBostonDay”
“Each year, the day serves as an opportunity to celebrate the resiliency, generosity, and strength demonstrated by the people of Boston and those around the world in response to the tragedy,” according to the One Boston Day organization’s website.
By late Saturday afternoon, the website had tallied more than 31,400 acts of kindness pledged in 2017.
In that spirit, other events across the city Saturday also marked the lives lost and the many thousands of people affected by the bombings.
Operation “Thank a Vet” called for people to hand-deliver thank-you packages to veterans in the Dorchester neighborhood. Hundreds participated in volunteer cleanup of Dorchester Avenue in the afternoon. The American Red Cross ran a blood drive with Boston Strong at the Sheraton Boston Hotel.
Abbott’s charity hosted the annual Heather Abbott Foundation Boston Marathon Brunch at the Met Back Bay restaurant to raise money for amputees and increase awareness of the challenges amputees face in affording customized prostheses and quality care and support, according to a statement from the Foundation.
The Boston police and Boston fire departments’ hockey clubs faced off in a charity match Saturday afternoon at the Warrior Ice Arena, according to a statement by the Boston Fire Hockey Club.
Copley Square was speckled with blue and yellow shirts of runners and fans who had attended the morning’s Boston Athletic Association 5K on Charles Street.
One runner, Ryan Wrigley, 35, had come from Birmingham, Ala., to run in his third consecutive Boston Marathon. It will be his 28th marathon overall.
Before running in marathons, Wrigley said, he had struggled from childhood asthma and sporadically smoked. The Boston Marathon, he said, is about trying new things, changing old habits, and getting stronger, as a community and as an individual.
“Running this does mean a lot about overcoming life’s troubles,” he said. “The city will come back a stronger city.”Nicole Fleming can be reached at firstname.lastname@example.org. Globe correspondent Felicia Gans and David Abel of the staff contributed to this report.