The twin bombs at the Boston Marathon killed Lu Lingzi, a 23-year-old Boston University student from China; 8-year-old spectator Martin Richard; and 29-year-old spectator Krystle Campbell. But it also injured more than 170 people: runners, couples, spectators, children. Some are in grave condition; some lost limbs or senses; all their lives will be forever touched by the bombings. Here are some of their stories.
CELESTE AND SYDNEY CORCORAN: HOLDING HANDS
Celeste Corcoran is a hairstylist on upscale Newbury Street, not far from the site of the bombing. Her daughter, Sydney, 17, is a senior at Lowell High School.
Celeste lost both legs below the knee and Sydney has severe injuries as well, cousin Alyssa Carter said in a fundraising page set up at GoFundMe.com. The page had raised more than $320,000 by Thursday evening.
Family members said Celeste was being incredibly positive. Her sister, Carmen Acabbo, told WJAR-TV that Celeste joked she "would be a hairstylist on wheels now."
Sydney has been through tough times before. She was hit by a car while crossing a street less than two years ago and fought to recover from a fractured skull, the Lowell Sun reported.
Nurses at Boston Medical Center were ultimately able to get the mother and daughter into the same hospital room.
"Their beds are pushed together," Carter wrote, "so they can hold hands."
ERIKA BRANNOCK AND NICOLE GROSS: A MOTHER'S GUILT
Carol Downing asks herself if she could have done something differently that would have spared her daughters from Monday's bombing.
Downing was about to cross the finish line in her first Boston Marathon when the bombs went off.
Daughter Nicole Gross, 31, is a personal trainer and triathlete in North Carolina at the Charlotte Athletic Club, where her husband, Michael, is general manager. She helped her mother prepare for the race.
Downing's younger daughter, Erika Brannock, 29, teaches 2-year-olds at a preschool at Trinity Episcopal Church in Towson, Md.
Erika's leg had to be amputated. Nicole's left leg was broken and right ankle was fractured, according to WCNC-TV. Michael had injuries including third-degree burns.
Downing told WCNC that it was supposed to be a fun weekend and that her daughters were so proud of her. Then the "what ifs?" came pouring out.
"What if I hadn't qualified? What if I hadn't come? What if I had gotten sick and couldn't come?" she asked. "What if I had run faster? What if they had stood someplace different?"
AARON HERN: SPECIAL VISITOR
Eleven-year-old Aaron Hern of Martinez, Calif., got a special visitor on Thursday.
The Kiwanis Club in his hometown posted a photo online showing Aaron and his family in his room at Boston Children's Hospital with first lady Michelle Obama. She and President Barack Obama came to Boston for an interfaith service and to visit people injured in the Boston Marathon bombings.
Aaron suffered leg wounds when the bomb went off. He was there with his father, Alan, and younger sister, Abby, to cheer his mother, Katherine, in her first Boston Marathon.
Aaron remained in critical condition Thursday, but The San Francisco Chronicle reported Aaron's mother said in a Facebook message to family and friends that he may be able to leave intensive care as soon as Friday. She said he had successful surgery Wednesday to close his wounds without the need for skin grafts.