Race volunteers and public officials rushed to the aid of wounded spectators, and the medical tent set up to care for fatigued runners was quickly converted to a trauma clinic. Runners and spectators were crying as they fled the billowing grey smoke rising from a running gear store overlooking the end of the course.
The explosion sent some runners tumbling to the pavement and others, already unsteady from the 42.195-kilometre run, were knocked down by those rushing toward the scene. A Rhode Island state trooper who ran in the race said the blasts tore limbs off dozens of people.
The blasts shattered the post-race euphoria of what had been a pleasantly uneventful 117th edition of the world's oldest and most prestigious annual marathon. Runners still on the course were diverted to the Boston Common; race officials said 4,496 runners had crossed the checkpoint at more than 24 miles but did not make it to the finish line.
"We're runners here, and running is such an event, you have people from 90 countries here for this race today," said Canadian runner Rob Watson, who finished 11th in the men's race.
"It brings everybody together. We're all here, we're all together, it's a great feeling to finish a marathon and there's such a camaraderie. It's so senseless, why would you do that? It's just so so upsetting. It's just terrible. Why would people do something like that?"
A year after record high temperatures sent unprecedented numbers of participants to the medical tent, temperatures in the high 40s greeted the field of 23,326 at the Hopkinton starting line. It climbed to 12 C by the time the winners reached Boston's Copley Square.
Desisa, of Ethiopia, won a three-way sprint down Boylston Street to finish in two hours 10 minutes 22 seconds and snap a string of three consecutive Kenyan victories.
"Here we have a relative newcomer," said Ethiopia's Gebregziabher Gebremariam, who finished third
In just his second race at 42.195 kilometres, Desisa finished five seconds ahead of Kenya's Micah Kogo to earn $150,000 and the traditional olive wreath. American Jason Hartmann finished fourth for the second year in a row.
"The Ethiopians run very good tactical races," defending champion Wesley Korir, a Kenyan citizen and U.S. resident, said after finishing fifth. "One thing I always say is, 'Whenever you see more than five Ethiopians in a race, you ought to be very careful.' As Kenyans, we ought to go back to the drawing board and see if we can get our teamwork back."
Jeptoo, 32, averted the Keynan shutout by winning the women's race for the second time. Jeptoo, who also won in 2006, finished in 2:26:25 for her first victory in a major race since taking two years off after having a baby.
After a series of close finishes in the women's race — five consecutive years with 3 seconds or less separating the top two — Jeptoo had a relatively comfortable 33-second margin over Meseret Hailu of Ethiopia. Defending champion Sharon Cherop of Kenya was another 3 seconds back.
Shalane Flanagan, of nearby Marblehead, was fourth in the women's division in her attempt to earn the first American victory in Boston since 1985. (Two-time winner Joan Benoit Samuelson, running on the 30th anniversary of her 1983 victory, finished in 2:50:29 to set a world record for her age group.)
"The hardest part about Boston is the Bostonians want it just as bad as we do, which really tugs at our heart," said Flanagan, a three-time Olympian. "We all want it too. We want to be the next Joanie."
Kara Goucher, of Portland, Ore., was sixth for her third top 10 finish in Boston as many tries. The last American woman to win here was Lisa Larsen-Weidenbach in '85; Greg Meyer was the last U.S. man to win, in 1983.
"There's just more pure numbers of African runners," said Goucher, who noted that the field of five American women with personal bests under 2:30 was the strongest in years.
"That's a good team of American women," she said. "One day the opportunity is going to be there."
This year it was the men's race with the sprint to the finish.
Desisa, 23, was among a group of nine men — all from Kenya or Ethiopia — who broke away from the pack in the first half of the race. There were three remaining when they came out of Kenmore Square with a mile to go.
But Desisa quickly pulled away and widened his distance in the sprint to the tape. It's Desisa's second victory in as many marathons, having won in Dubai in January in 2:04:45.
Japan's Hiroyuki Yamamoto was the first winner of the day, cruising to victory in the men's wheelchair race by 39 seconds over nine-time champion Ernst Van Dyk of South Africa. Tatyana McFadden, a Russian orphan who attends the University of Illinois, won the women's race.
Race day got started with 26 seconds of silence in honour of the victims of the Sandy Hook Elementary School shooting. A little more than two hours later, the lead runners passed the Mile 26 marker, which was decorated with the Newtown, Conn., seal and dedicated to the memory of those killed there.
— With files from The Canadian Press.Suggest a correction