[Updated at 10:18 p.m. ET]

BOSTON—Police have nabbed the 19-year-old suspected Boston Marathon bomber, after a day-long manhunt that completely shut down the city of Boston and several suburbs and left one police officer dead. Some Bostonians flooded into the streets cheered the news, celebrating an end to five days of fear since the bombs wounded more than 175 people and killed three.

An ambulance arrived at the scene to take the wounded suspect, Dzhokhar A. Tsarnaev, to a hospital. Massachusetts State Police Col. Timothy Alben said he is in serious condition.

Tsarnaev was found in a boat in the yard of a home on Franklin Street, close to where he and his older brother engaged in a shootout with police nearly 24 hours earlier. The homeowner discovered Tsarnaev when he saw blood on the outside of his boat and then lifted the tarp to find a person, covered in blood, inside. Police used a heat-detecting device on a helicopter to find out that he was still inside, and exchanged gun fire with the suspect for the next hour, before he was apprehended.

Watertown residents--finally able to leave their homes around 8:45 p.m.--broke into cheers and applauded police officers after word spread that the suspect was in custody.

"We're so grateful to bring justice and closure to this case," Alben said at a 9:30 p.m. press conference. "We're exhausted ... but we have a victory here tonight." Boston Police Commissioner Ed Davis said he could find no explanation for the "savagery" of the attacks, but that the capture made him proud to be a Boston police officer.

"We've closed an important chapter in this tragedy," President Barack Obama said in brief remarks at the White House Friday night, noting there were still many unanswered questions about the Tsarnaevs' actions.

"Whatever they thought they could ultimately achieve, they failed," Obama said. Americans, he said, "refuse to be terrorized."

Just a few hours earlier, at 6:00 p.m ET, police announced that the 19-year-old suspected bomber had eluded capture after fleeing from police on foot early Friday morning.

Thousands of law enforcement officers conducted a nearly 24-hour door-to-door manhunt for Dzhokhar Tsarnaev, who is suspected of helping his brother plant two bombs near the finish line at Monday's Boston Marathon that wounded more than 170 people and left three dead.

Officials announced at 6:00 p.m. news conference that they had been unable to apprehend the suspect, despite combing through a 20-block area of the Boston suburb of Watertown and shutting down the city's entire public transportation system in an effort to prevent him from fleeing. They said they did not know if he had a car, or if he was still on foot. The home where Tsarnaev was eventually discovered was outside the 20-block perimeter, and had not been searched.

Gov. Deval Patrick lifted his previous "shelter in place," or lockdown, order for the city of Boston and many surrounding areas of the city at 6:00 p.m.. But Patrick urged Bostonians to continue to be "vigilant" as the "very dangerous" armed suspect has not been apprehended.

An overnight police chase and shootout left Dzhokhar's 26-year-old brother, Tamerlan Tsarnaev dead and Dzhokhar on the lam.

Federal investigators had released photos and videos of the two men hours earlier, showing them in the vicinity of the marathon finish line before the twin explosions. Dzhokhar Tsarnaev was seen placing a backpack on the ground minutes before the blast, investigators said.

One MIT police officer was killed and another transit police officer seriously wounded during the violent spree. The city of Boston and its surrounding areas ground to a standstill for hours as police went door to door searching for the suspect in the suburb of Watertown.

Police said they had uncovered several improvised explosive devices (IEDs) in Watertown and in the brothers' home in Cambridge.

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