The arrest of 19-year-old Dzhokhar Tsarnaev of Cambridge ended an unprecedented daylong siege of Greater Boston, after a frantic night of violence that left one MIT police officer dead, an MBTA Transit Police officer wounded, and an embattled public — rattled again by the touch of terrorism — huddled inside homes.

Tsarnaev’s elder brother and ­alleged accom­plice — 26-year-old Tamerlan Tsarnaev, the second suspect in Monday’s Boston Marathon attack — was pronounced dead early Friday morning at Beth Israel ­Deaconess Medical Center, ­after suffering shrapnel and bullet wounds in a gunfight with police.

“It’s a proud day to be a Boston police officer,” Police Commissioner Edward F. Davis told his force over the radio moments after the arrest. “Thank you all.”

President Obama, addressing the nation from the White House, ­applauded Boston for not allowing the terrorists to prevail.

“They failed because the people of Boston refused to be intimidated,” the president said.

Friday will be remembered as the day the city stood still, after Governor Deval Patrick asked the people of Boston and the nearby communities of Watertown, Waltham, ­Newton, Belmont, and Cambridge to “shelter in place” — stay inside, lock the door, and don’t open it for anyone except police in uniform — while the younger ­Tsarnaev was on the loose.

A city of some 625,000, in a ­metropolis of 2 million, screeched to a halt. Heavily armed officers patrolled eerily empty streets that looked like the set of an apocalyptic movie. The MBTA halted its trains, buses, and subways. Taxi service was temporarily frozen. Amtrak stopped service between Boston and Providence. Officials asked businesses across the region not to open. The Red Sox and Bruins games were postponed. And the campus of the University of Massachusetts Dartmouth, where ­Dzhokhar Tsarnaev is a student, was evacuated and closed.

The day began with bomb blasts and gunshots on a street in Watertown, where police said more than 200 rounds were fired in the battle.

While his brother was taken to the hospital, where he was pronounced dead, Dzhokhar Tsarnaev survived and escaped on foot. Local, state, and federal law enforcement officers — includ­ing the Secret Service, K-9 teams, ­explosives experts, and SWAT officers — searched door to door for the suspect throughout Friday. Police in ­helicopters scoured the streetscape from above. More than 1,000 officers participated in the hunt.

By 6 p.m., frustrated officials relaxed the rule and allowed residents to leave their homes. The people of Watertown began to venture outside.

But within an hour, the crack of gunshots again blasted through the neighborhood. ­Sirens blared, and officers on foot scrambled down Franklin Street.

Police found Dzhokhar ­Tsarnaev hiding on a boat stored in a backyard on ­Franklin Street. Police ­exchanged gunfire with him before capturing him alive. Spontaneous celebrations erupted across the region, from the ­Boston Common to the Back Bay streets near the bombing.

The boat’s owners, a couple, spent Friday hunkered down under the stay-at-home order. When it was lifted early in the evening, they ventured outside for some fresh air and the man noticed the tarp on his boat blowing in the wind, according to their his son, Robert Duffy.

The cords securing it had been cut and there was blood near the straps. Duffy’s father called police, who swarmed the yard and had the couple evacuated, Duffy said.

Residents, who had barricaded themselves in their homes for nearly 20 hours, were still deeply shaken. “I’m so happy they got these guys,” said Tom Sheridan, 35, an interior painter from Watertown, as he cheered police cruisers and ambulances as they drove by on Mount ­Auburn Street. “But I’m worried there are more people out there like that. It won’t be the same.”

Tsarnaev was wounded and taken to a hospital. In an interview late last night, Patrick said he is “hoping very deeply he survives those wounds, because I’ve got a lot of questions and I know investigators have a lot of questions for him.”