He was an eight-year-old boy who had just hugged his father.
The youngest victim of the Boston Marathon bombings was Martin Richard, who was killed by the blasts while his mother and his six-year-old sister, Jane, were gravely injured.
Martin was the second of the three children of Bill Richard and Denise O'Brien Richard of Dorchester, a Boston suburb.
"My dear son Martin has died from injuries sustained in the attack on Boston. My wife and daughter are both recovering from serious injuries," Mr. Richard said in a statement released to the media Tuesday afternoon.
"We thank our family and friends, those we know and those we have never met, for their thoughts and prayers. I ask that you continue to pray for my family as we remember Martin," he added, saying that the family wanted to grieve in private.
"They lost their son who had an infectious smile to a completely senseless act. Denise and their daughter are still in serious condition. So absolutely tragic," a friend, Nina Marchese, wrote on Facebook.
"Martin, you were the sweetest, funniest boy. I'm going to miss you so much, but now you are an angel," a cousin, Jackie Hernandez, tweeted.
An acquaintance posted a past photo showing Martin in his elementary classroom, holding a sign he had prepared for a school march last year, saying: "No more hurting people. Peace."
The NBC affiliate WHDH reported that Martin's mother had surgery because she suffered a brain injury. Martin's sister was severely injured in a leg.
Martin was in the area near the finish line with his family and the third-grader had just hugged his father, according to the Boston Globe.
The oldest sibling, Henry, was uninjured.
The family was well-known in Dorchester because both parents are very active in the community.
On the doorstep of their home on Monday night, a single candle burned. Someone had written on the sidewalk the word "Peace."
"What a gift. To know him was to love him," said longtime friend Judy Tuttle, who remembered sitting at the dining room table having tea with Ms. Richard while Martin did his homework.
"He had that million-dollar smile and you never knew what was going to come out of him. Denise is the most spectacular mother that you've ever met and Bill is a pillar of the community. It doesn't get any better than these people."
Neighbour Betty Delorey, 80, said Martin loved to climb the neighbourhood trees and hop the fence outside his home.
"I can just remember his mother calling him, 'Martin!' if he was doing something wrong," she said. "Just a vivacious little kid."
Ms. Delorey had a photo showing Martin dressed as the character Woody from the Toy Story films, wearing a cowboy hat, a sheriff's badge, jeans and a big smile. His sister, Jane, was at his right, dressed as Woody's friend, Jesse. Their older brother, Henry, was to their left, dressed as Harry Potter.
"I'm sick to my stomach," she said. "It's hard to say anything really."
The children's father is the director of a local community group, and an avid runner and bicyclist.
Ms. Richard works as a librarian at the Neighborhood House Charter School, where Martin was a third-grader and Jane attends first grade.
- With a report from AP
Editor's Note: An earlier version of this article and headline incorrectly said that Bill Richard ran in the marathon. He was a spectator.