Boston University student Aaron Wengertsman, 19, wrapped himself in an American flag. He was on the marathon route a mile from the finish line when the bombs exploded.
"I'm glad they caught him alive," he said of one of two brothers authorities say were responsible for the explosions. "I thought people might be more excited, but it's humbling to see all these people paying their respects."
As Wengertsman and dozens of others held a solemn commemoration Friday night for the victims of the blasts, others took to the streets of Boston and beyond to celebrate the capture of the surviving suspect following a manhunt that left the city largely paralyzed.
In Boston's Dorchester neighborhood, where an 8-year-old boy killed in the bombing lived, people set off fireworks.
Boston University juniors Brendan Hathaway and Sam Howes gave high fives to strangers as they walked down the street bathed in the flashing lights from Kenmore Square's iconic rooftop Citgo sign.
"This was like our first opportunity to really be outside without feeling like there imminent danger," said Hathaway, a mechanical engineering student from nearby Newton. "It was close to home for me."
At Boston Common, Beth Lloyd-Jones said it felt like she had her city back. She was blocks away from the blast on Monday in her south end home.
"It's personal," she said, noting that she's planning her wedding for the public library building adjacent to where the bombs exploded.
"That could have been any one of us," she said of the victims. "Now I feel a little safer."
The surviving suspect, 19-year-old Dzhokhar Tsarnaev, was taken to a hospital after engaging in a firefight with police while hiding out in a parked boat in a Watertown backyard. Earlier in the day, his 26-year-old brother, Tamerlan Tsarnaev, had been killed in a gunbattle and car chase during which he and his younger brother hurled explosives at police from a stolen car, authorities said. During the getaway attempt, the brothers killed an MIT policeman and severely wounded another officer, authorities said.
"Never in my wildest dreams did I think that this would result in a shootout in Watertown," said Sheamus McGovern, of neighboring Belmont.
Less than 24 hours after the shootout, police officers and firefighters stood grim-faced with guns and rifles, lining the street leading to the property about a mile away where the younger brother was believed to be holed up in the boat.
Reporters and spectators lined up on the other side. The mood was tense, with the few neighbors who ventured out hugging and crying as they heard bangs. Others merely looked on curiously.
Then, one officer slowly started clapping. Then it spread to the crowd. Then loud cheers broke out.
People in the crowd started asking, "Is he alive?" One of the officers nodded, yes. Any time a first responder emerged from the street, there was loud applause.
"They finally caught the jerk," said nurse Cindy Boyle, 41. "It was scary; it was tense." She said she knew when police started clapping that everything would be all right.
Celebratory bells rang from a church tower in Watertown after the capture. Teenagers waved American flags in the center of town. Every car that drove by honked. Every time an emergency vehicle went by, people cheered loudly.
Liz Rodgers, a 65-year-old attorney, took one of the pieces of yellow police tape and tied it around her neck like a necklace.
"When you see your town invaded like this, it's stunning," she said. "Everyone in Watertown is just so grateful that he's caught and that we're liberated."
The jubilation was widespread. The mayor of Boston tweeted, "We got him!" And at the home of the New York Mets, spectators leapt to their feet and cheered when the news spread during a game against the Washington Nationals.
Hundreds of people marched down Commonwealth Avenue, chanting "USA" and singing the Red Sox anthem "Sweet Caroline" as they headed toward Boston Common. Police blocked traffic along part of the street to allow for the impromptu parade.
"I can finally sleep tonight," said 27-year-old Lisa Mara, standing along Boylston Street, just a few blocks from her home.
Lindsay reported from Watertown, Mass. Associated Press writers Allen G. Breed, Bridget Murphy and Katie Zezima in Boston contributed to this report.
PHOTOS: The celebration in Boston