Must-see marathon moments

Kenyan Geoffrey Kirui set the pace in the 121st Boston Marathon, crossing the finish line with a time of 2:09:37. Fellow KenyanEdna Kiplagat claimed the women's title with a time of 2:21:52. At 37 years old, Kiplagat was the second oldest woman to ever win the marathon.

While the titles are the biggest story of the event, the focus since the Boston Marathon bombing in 2013 has been as much on the human side as the race itself.

In 2014, Eritrean-born American runner Meb Keflezighi crossed the marathon's finish line wearing the names of the victims of the prior year's bombing proudly on his chest. This year, Keflezighi announced that this would be his last time running in the Patriots' Day race. Keflezighi finished 13th in the race and embraced the family of Martin Richard, the 8-year-old victim of the bombing.

In what went down as the iconic image of this year's marathon, Jose Luis Sanchez, a Marine who lost part of his leg to an improvised explosive device (IED) while serving in Afghanistan, ran the marathon on his prosthetic leg carrying the American flag. He finished the race in 5:46:13.

Kathrine Switzer, the first woman to run the Boston Marathon with an official number in 1967, participated in the 50th anniversary of her groundbreaking run. In 1967, she entered by signing up with her initials, giving officials the impression that she was a man. Switzer had not participated in the Boston Marathon since 1976, and her run marked the 40th marathon of her career. She finished with a time of 4:44:31.

The Tufts Marathon Team sent 35 runners to participate in the marathon, as it does every year. According to the team's fundraising webpage, it raised a combined $239,454 to support nutrition, medical and fitness programs at Tufts, including research on childhood obesity at the Friedman School of Nutrition Science and Policy. This topped the 2016 total of $228,830.