Hundreds of people gathered in Boston on Tuesday night at two vigils held to honor the victims of twin bomb blasts at the finish line of the city's storied marathon the day before. The bombings, which President Obama has called an act of terror, killed three people and wounded more than 170, many of them critically. Investigators can't yet say who they think was behind the gruesome attack, but relatives and friends are sharing memories to tell the world about the people who died.

The first victim identified was Martin Richard, 8. The third-grader was standing near the finish line with his mother, Denise, and his younger sister. Martin's dad, Bill, is a runner, and he had competed in the marathon before, though not this year. The family liked to go out on race day and watch. When the blasts tore through the crowd, Martin was killed. His sister, Jane, reportedly lost a leg. His mother suffered a brain injury, and underwent emergency surgery to save her life. Bill Richard asked for people to keep his family in their prayers.

Mourners carrying American flags and candles gathered in a park in the family's middle-class neighborhood, where Martin Richard used to play baseball. A local pastor said a prayer. Friends and neighbors stopped by the family's home to pay respects, leave flowers, and grieve. The Richards are a "typical, all-American, lovely family," a neighbor, Margaret Admirand, told NBC News. "It's devastating. He was an adorable little boy," Admirand said. "It's very hard to talk about. He was a sweet little kid."

Twenty-nine-year-old Krystle Campbell, the second victim identified, had gone out with her best friend to watch the latter's boyfriend cross the finish line. Campbell's friend was seriously injured when shrapnel cut an artery in her leg. Hospital staff reportedly initially told Campbell's father, William, that his daughter was alive and being treated. When he arrived, however, he saw that the patient was his daughter's friend, who just happened to have been carrying Krystle Campbell's ID. Later, the authorities asked him to look at a photo of a woman who had been killed — that's how he learned his daughter had died.

Krystle Campbell's grandmother said the young woman had been going to watch the marathon every year "since she was a little girl." Friends and relatives described Campbell, a restaurant and catering manager, as a hard worker. The gym where she exercised issued a statement calling her "salt of the earth," and notifying people who knew her there that she had been killed instantly. William Campbell said she was just a "dream" daughter. "My daughter was the most lovable girl," he told Yahoo News. "She helped everybody and I'm just so shocked right now. We're just devastated." "This is just a waste," Krystle Campbell's mother, Peggy, said. "She loved pets and she loved people."

The last of the three victims to be identified was a Chinese graduate student at Boston University. The Chinese Consulate confirmed the woman's death, but said that her family had asked that no personal details be released. Several sources — including a classmate and a state-run newspaper in her home city, Shenyang, in China's rust belt — identified the victim. She had reportedly gone to watch the race with a friend.

According to mournful messages on Chinese internet sites, she was in her mid-20s, and studying for a career in finance. Users of Weibo, a Chinese microblogging service similar to Twitter, left more than 10,000 messages to her through her account. "You are in heaven now," one message said, "where there are no bombs."