For just a few minutes, it seemed like the dragnet that had shut down a metropolitan area of millions while legions of police went house to house looking for the suspected Boston Marathon bomber had failed.

Weary officials lifted a daylong order that had kept residents in their homes, saying it was fruitless to keep an entire city locked down. Then one man emerged from his home and noticed blood on the pleasure boat parked in his backyard. He lifted the tarp and found the wounded 19-year-old college student known the world over as Suspect No. 2.

Soon after that, the 24-hour drama that paralyzed a city and transfixed a nation was over.

Dzhokhar Tsarnaev's capture touched off raucous celebrations in and around Boston, with chants of "USA, USA" as residents flooded the streets in relief and jubilation after four tense days since twin explosions ripped through the marathon's crowd at the finish line, killing three people and wounding more than 180.

The 19-year-old — whose older brother and alleged accomplice was killed earlier that morning in a wild shootout in suburban Boston — was hospitalized in serious condition Saturday, unable to be questioned to determine his motives. U.S. officials said a special interrogation team for high-value suspects would question him without reading him his Miranda rights, invoking a rare public safety exception triggered by the need to protect police and the public from immediate danger.