The concept of sports as a distraction, as a relaxant from the stress and seriousness emanating from everyday life, became magnified right after the 9/11 terrorist attacks. When football and baseball games resumed following a brief period of postponement, America found comfort in sporting events that were at once more insignificant, and yet more important, than ever.

On Monday in Boston, the concept overturned. When two bombs exploded near the end of the Boston Marathon route, killing three people and wounding nearly 180 more, a sporting event was itself the scene of terrorism. The tonic had become the target.

True, it wasn’t the first time that terrorists had done their dirty work at a major sporting event. Israeli athletes were taken hostage and later murdered during the Munich Summer Olympics in 1972, and two people were killed when a homemade bomb exploded in the Centennial Olympic Park at the 1996 Summer Games in Atlanta. But Monday’s attack was different in that it happened while the actual event was under way, while fans were still cheering and runners still running.

Four Wiltonians were among those who had completed the race before the explosions, and neither they nor their families or friends were harmed. One of those runners, Mark Begor, finished just a few minutes before the first bomb detonated. His wife, Kristen, had been watching from in front of the building where the initial explosion took place, but then started walking toward the finishing area and was 15-20 feet away from the blast. She said her husband, who usually finishes marathons in three and a half hours, was running more slowly because he wasn’t feeling well. She was fortunate, though, that he didn’t run any slower.

Another area finisher was Ridgefielder Megan Searfoss, the founder of the popular Run Like A Mother 5K race, who crossed the finish line about 20 minutes before the explosions. Before leaving to meet up with Searfoss, her husband and daughter had been sitting in the grandstand across the street from the blasts. Joining them in the stands were family members of the victims of the Sandy Hook Elementary School shootings in December. The final mile of the Boston Marathon had been dedicated to the Newtown families, and there was a 26-second moment of silence before the race in honor of the victims.

“They had to witness another tragedy,” said Searfoss. “It’s really beyond comprehension.”

Searfoss said that one of her observations as she neared the finish line was the large number of policemen.

“Everywhere you looked there seemed to be a policeman,” she said. “And throughout the race there were policemen and National Guardsmen. Safety wasn’t something I was concerned about.”

Until Monday, terrorist bombs and blasts and explosions during marquee American sports events, such as the Super Bowl, had remained the province of suspense novels and mediocre films. The 9/11 attacks led to heightened security measures at games, resulting in lines of spectators waiting to go through metal detectors, have a wand waved around them, or submit their bags for searches. But whatever frustration arose from those delays could be relieved by the thought of a safer environment and a spotless track record.

Now there is an unfortunate precedent; the safety Searfoss and everyone else felt was suddenly not enough.

On Sunday, Searfoss paid $110 to buy an official Boston Marathon runners jacket. The jacket, which bears the name of the race and the year the runner ran it, is something of a conversation starter among runners.

“People see it and want to talk about the race,” she said. “The Boston Marathon just has such a special tradition.”

Searfoss said she had planned to proudly wear the jacket on Tuesday, the day after the race. She didn’t.