The president and the first lady show support for the city that lost three people and saw scores more injured at the Boston Marathon.
President Barack Obama sought to inspire a stricken city and comfort an unnerved nation Thursday, declaring that Boston "will run again" and vowing to hunt down the perpetrator of the twin blasts that brought mayhem and death to the Boston Marathon.
"If they sought to intimidate us, to terrorize us ... It should be pretty clear right now that they picked the wrong city to do it," Obama said.
The president spoke at an interfaith service in Boston honoring the three people killed and more than 170 injured when a pair of bombs ripped through the crowd gathered Monday afternoon near the finish line of the famous race.
"We may be momentarily knocked off our feet," Obama said. "But we'll pick ourselves up. We'll keep going. We will finish the race."
Defiant, Obama demeaned the still unidentified culprit or culprits as "small, stunted individuals who would destroy instead of build, and think somehow that makes them important."
"Yes, we will find you," he declared as applause filled the Cathedral of the Holy Cross. "And, yes, you will face justice. We will find you. We will hold you accountable."
Obama spoke as his second-term as president is increasingly burdened by terror, politics, and disaster. In the aftermath of Boston's deadly blasts Monday, Obama lost a fight for gun control measures in the Senate, was the target, along with a U.S. senator, of letters that showed traces of poisonous ricin, and awoke Thursday to news of a powerful fertilizer plant explosion that devastated a small Texas town.
The letters alone -- one addressed to Obama and another to Sen. Roger Wicker, R-Miss. -- evoked eerie parallels to the anthrax attacks that followed the terrorist attacks of Sept. 11, 2001. Authorities arrested a Mississippi man Wednesday in connection with the letters and charged him with threatening the life of the president.
It was against that backdrop that Obama and his wife, Michelle, came to Boston Thursday morning, joining the packed cathedral for a "Healing Our City" service. The Obamas sat at the front of the church next to Massachusetts Gov. Deval Patrick as the service began.
Obama listened from his pew as Boston Mayor Thomas Menino praised the response of his city.
"Nothing will take us down because we take care of one another," Menino said. "Even with the smell of smoke in the air and blood in the streets and tears in our eyes, we triumphed over that hateful act."
Moments later, Patrick said: "We will grieve our losses and heal. We will rise, and we will endure. We will have accountability without vengeance, vigilance without fear."
Sustaining that uplifting theme, Obama recalled his days as a law student at Harvard and declared, "There is a piece of Boston in me."
"Every one of us has been touched by this attack on your beloved city, every one of us stands with you," he said.
"This time next year, on the third Monday in April, the world will return to this great American city to run harder than ever and cheer even louder for the 118th Boston Marathon," he said.
"Your country is with you," Obama added. "We will all be with you as you learn to stand and walk and yes, run again. Of that I have no doubt, you will run again."
Before the service, Obama and the first lady met at the cathedral with members of the family of Krystal Campbell, one of the three killed Monday.
After the observance, Obama visited a gymnasium across the street from the church to thank volunteers who worked at the marathon, saying they displayed "the very best of the American spirit."
"There's something about that that's infectious. It makes us want to be better people," he said.
Obama then rode to Massachusetts General Hospital where he met privately with patients, their families and hospital staff.
White House spokesman Josh Earnest said Obama received a briefing from national security adviser Lisa Monaco on the status of the investigation into the Boston blast before departing the White House. Accompanying Obama aboard Air Force One were members of the Massachusetts congressional delegation, including Sens. Elizabeth Warren and Mo Cowan.
The service was underway as investigators were looking for two men captured on video near the scene of Monday's bombing, NBC News reported. One of the men was seen dropping off a bag then walking away from the site of the second explosion near the race's finish line.
The president has stepped into this role as the nation's consoler in chief many times before in his presidency, most recently in December after the massacre of 20 first-graders and six educators at an elementary school in Newtown, Conn. Before that, there were the deadly shootings in Aurora, Colo., Tucson, Ariz., and Fort Hood, Texas, as well as the natural disasters that tore apart towns and neighborhoods in Missouri and the New York-New Jersey area.