Hundreds of thousands of people have been asked to remain in their homes while police hunt for Tsarnaev. Click here for live updates.

Authorities in Watertown, Mass. are engaged in a citywide manhunt for one suspect of the Boston Marathon bombing after the other was killed in a shootout early Friday morning. Details are still sketchy, but most outlets are reporting that the suspect still on the loose (the one in the white hat in these photos) is Dzhokar A. Tsarnaev, 19, of Cambridge, a Chechen who has been living in the U.S. as a legal permanent resident for at least a year. The deceased suspect, killed in a gun battle with police around 2 a.m., is apparently his 26-year-old brother, Tamerlan.

The long night began at 10:48 Thursday evening, when gunshots were heard outside of MIT's Stata building. The two suspects, after robbing a 7-11, shot and killed an MIT police officer. They then hijacked a car and engaged police in a confrontation involving guns and explosives in the Watertown area.

Authorities have confirmed that these are their Boston Marathon bombing suspects. Watertown remains locked down, with more than 300,000 people instructed to stay in place. [top image via Shawna England]

Updates:

5:05 PM: Here is the start of this nonsense, courtesy of Senator Lindsey Graham:

4:39 PM: Jeff Bauman, the bombing victim who lost both legs before helping the FBI identify Dzhokar and Tamerlan, has resorted to fundraising online to pay for his medical bills. Despite living in Massachusetts, the state whose healthcare system gave rise to Obamacare, Bauman is a member of the 1.9 percent of Massachusetts residents who are uninsured.

4:19 PM: The Daily Mail has found Tamerlan's wife and three-year-old daughter.

3:30 PM: Amtrak service between New York and Boston is discontinued, and tonight's Red Sox game has been cancelled.

3:04 PM: Dzhokar was apparently hanging out at his dorm room at UMass Dartmouth yesterday:

2:55 PM: Megyn Kelly wonders if you Forgot About Dre, at left.

2:03 PM: Police are now looking for a green Honda Civic, reported by a Jalopnik commenter who knew him to be Dzhokar's car.

12:31 PM: A vehicle with Massachusetts plates is being examined by a bomb squad in Niagara falls.

12:28 PM: Pete Williams of NBC reports that Dzhokar Tsarnaev became a U.S. citizen on 9/11 last year:

12:21 PM: Tamerlane Tsnarnaev flew to Russia and stayed out of the country for six months, MSNBC reports:

12:01 PM: The Tsarnaev's sister is being interviewed by the FBI. The Star-Ledger had found her earlier:

"They were great people. I never would have expected it," said the woman, of the suspects in Monday's bombing. "They are smart–-I don't know what's gotten into them." [...]

"No I'm not okay-no one is okay right now," she said. "I'm hurt for everyone who has been hurt. I'm sorry for all the people who are hurt and for all the people who lost their lives."

11:55 AM: Not everyone is #PrayingForBoston:

11:31 AM: In his second interview, the Tsarnaev's uncle re-iterated his belief that they undertook the bombing because they are "losers."

11:27 AM: This is likely Dzhokar's Twitter account.

11:09 AM: Ramzan Karimov, the Head of the Chechen Republic, released a statement on, uh, Instagram. Very rough, abridged, Google-assisted translation follows:

Tragic events took place in Boston. The blast killed people. We have previously expressed condolences to the people of the city and the people of America. [...] Any attempt to make the connection between Chechnya and Tsarnaevymi, if they are guilty, will be made in vain. They grew up in the United States, their attitudes and beliefs were formed there. It is necessary to seek the roots of evil in America. From terrorism to fight the whole world. We know better than anyone else. We wish recovery to all the victims and share the feelings of sorrow of Americans. # # Boston # bombing investigation

10:26 AM: Connecticut says it's found the CRV and is directing questions to Boston.

10:08 AM: Police have put out an alert for a grey Honda CRV that they believe may be heading south through Connecticut:

According to NBC News, police are now looking for two suspects in Boston:

MSNBC is apparently reporting that authorities have surrounded a train in Connecticut that may contain a third suspect.

10:05 AM: We're updating information about the suspects here as it comes out.

10:04 AM: NBC tweets a photo of an empty boston:

9:38 AM: The MIT police officer killed last night has been identified as Sean Collier, 26, of Somerville.

9:00 AM: According to several outlets, police believe that Tamerlan Tsarnaev was wearing explosives when he was killed, and are worried that Dzhokar could be, too.

8:38 AM: Police officers and a SWAT team have surrounded a house in Watertown.

8:25 AM: The officer shot and wounded in Watertown is Richard Donohue, a 33-year-old transit officer.

8:17 AM: The entire city of Boston is being asked to shelter in place as the manhunt continues. Taxi service has been suspended pending further notice.

7:43 AM: NBC and the Times are both reporting that the dead suspect is Tamerlan Tsarnaev, 26.

7:15 AM: NPR's Dina Temple-Raston reports that third person (described as an "accomplice") has been arrested.

6:47 AM: AP is reporting that both bombers are from "Russia region near Chechnya" and have lived in the U.S. for at least one year; the surviving suspect, according to AP and NBC, is 19-year-old Dzhokhar A. Tsarnaev of Cambridge, Mass., possibly this former scholarship winner.

6:32 AM: Big concern is not only the bomber himself, but the possible explosives he has left around the neighborhood. A long night looks like it might turn into an even longer day for Boston residents.

6:20 AM: The suspects apparently told the man they carjacked late last night that they were the marathon bombers.

6:15 AM: If you're a resident of Watertown, Brookline, Newton, Belmont, Waltham, Cambridge, or Allston-Brighton, authorities are telling you to stay indoors while they search for the remaining bombing suspect.

6:10 AM: Residents are now leaving their homes one by one in Watertown as SWAT teams enter their homes as they exit, checking them for explosives, seeing if their house has been rigged by the suspect.

6:00 AM: Boston public transit, the MBTA, will remain shut down this morning. Harvard, MIT, Boston University, and Emerson have canceled classes, amid public safety concerns. All Boston public and private schools have now been canceled.

5:30 AM: At a press conference at Beth Israel Hospital, doctors explained that the first suspect arrived at the hospital with severe injuries that included innumerable gun shot wounds, and burns from a blast. He had traumatic injuries to his torso, possibly from a bomb. He was pronounced dead around 1:30 AM.

5:20 AM: Here's a Google Map of tonight's events:


View Shootings 4/19 MIT && Carjacking related to boston bombers in a larger map

5:00 AM: Not confirmed, but a BPD scanner apparently identified the two bombers as Mike Mulugeta (now deceased) and Sanil Tarpathi, who is currently hiding from authorities somewhere in Watertown.

Here is some new video of the shootout between the two suspects and police officers:

4:55 AM: The package at MIT is harmless, say officials. So how about that? Some good news!

4:46 AM: A suspicious package has been found at MIT, where the bombers killed an officer late last night.

4:33 AM: Sources tell WHDH Boston that there are explosive devices scattered throughout the residential neighborhoods around Watertown.

4:20 AM: Col. Timothy Alban of the Boston State Police just held a press conference outlining the events of last evening and this morning. Here goes:

After robbing a 7-11 in Cambridge at around 10:30 PM Thursday, the two suspects shot an MIT police officer in his car, and then carjacked a Mercedes SUV. They held the driver hostage, then released them at a gas station a half-hour later.

They were discovered in Watertown driving the SUV, and were pursued by the Watertown Police Department and Transit Police. They exchanged gunfire with the police departments, discharging several explosives from their the car. One transit officer was shot and is in serious condition, and one suspect was shot and killed, while the other escaped.

Col. Alban stressed that the most important message for public safety was that everyone in Watertown should shelter in place, and call 911 if they see anyone suspicious. Motorists should not stop for anyone. According to the video from 7-11, the suspect is dressed in a grey hoodie, is Caucasian, has brown curly hair, and is "armed and dangerous."

4:15 AM: The Mass State Police have released this picture of suspect #2, taken from surveillance footage of the earlier robbery.

4:11 AM: The driver the marathon bombers hijacked was held by them for a half hour at gun point, before they were released safely.

4:05 AM: 2 SWAT teams have descended on a commercial building in Watertown, where they believe the remaining suspect is.

4:01 AM: Police are now staging in Arsenal Mall, and State Police are asking media to clear out of the area. Officers might be waiting for sunrise to storm whatever home they believe the remaining Marathon bomber is hiding in.

3:51 AM: State Police are going door-to-door in Watertown, searching for suspect #2, who it increasingly looks like is Sunil Tripathi. Update: As has become clear, missing Brown student Sunil Tripathi was not the bomber, despite his name being used by Boston P.D. on the police scanner.


3:41 AM: These two updates from the Mass State Police tell Watertown residents to watch out for the remaining suspect —

3:14 AM: According to Pete Williams at NBC News, a pressure cooker was found at the scene in Watertown.

3:08 AM: The crime scene continues to move through Watertown and officials are asking residents to stay indoors and not let anyone into their home.

3:06 AM: The family of Sunil Tripathi, the missing Brown student who Reddit believed was one of the suspects, has taken down the Facebook page dedicated to find him. Here is a cached version of it. He could be holed up in a Watertown home right now, in custody, or dead. Update: As has become clear, missing Brown student Sunil Tripathi was not the bomber, despite his name being used by Boston P.D. on the police scanner.

3:05 AM: It has come out that a transit officer was shot earlier in the evening and is in serious condition.

3:01 AM: WHDH confirms that these are the Boston Marathon bombing suspects and that one is dead.

3:00 AM: The State Police have confirmed that one suspect is accounted for, while one remains at large.

2:46 AM: Police have surrounded a Watertown house on Quimby Street, where they believe the remaining suspect is hiding. Federal and local authorities have poured into the residential neighborhood.

2:34 AM: The Boston Globe is reporting that these are the marathon bombers. WHDH says one is dead and the other is still on the loose, but the Globe says the captured suspect is still alive.

2:25 AM: Andrew Kitzenberg posts a picture of a bullet that went through his Watertown home during a shootout.

2:20 AM: Photo of the FBI on the scene in Watertown by @christinawilkie

2:14 AM: A second suspect remains at large, reports Boston's WHDH. The FBI is now involved in the investigation, lending Federal involvement to what would normally be a crime dealt with solely by local authorities.

2:09 AM: ABC's Joshua Hoyos is reporting that there is no connection to the Marathon Bombings.

1:49 AM: Seth Mnookin has posted a photo of the arrest of one of the suspects:

1:25 AM: It appears a suspect is in custody:

1:18 AM EST: Police officers are approaching a suspect in heavy armor.

1:15 AM EST: Science Writer Seth Mnookin is on scene:

1:01 AM EST: Police are taking cover and backing away from a suspect, says WHDH reporter Adam Williams, now at the scene of the confrontation. He has heard that the suspect has a hand grenade.

12:58 AM EST: Police feed reports that explosives have been detonated in Watertown. At least two officers have been hurt.

12:51 AM EST: Police have cornered the suspects at Adams St in Watertown after they hijacked a car. There are reports of gunshots, and an intense confrontation between police officers and the suspects. WHDH-Boston reports that "there is a strong smell of gun powder in the air." Authorities still unsure if the suspects are related to the marathon bombing.

12:14 AM EST: A statement from the Cambridge District Attorney says that the fatal shooting occurred when the MIT campus police officer was reporting to "a disturbance in the area." He was found by other officers evidencing multiple gunshot wounds. There have been no arrests yet, as officers continue to search the area.

12:01 AM EST: NBC Connecticut is reporting that the MIT police officer has died.

11:49 PM EST: Police are actively trying to corner the suspect. The MIT police officer has been confirmed to have sustained "life-threatening injuries" according to WHDH-Boston. MIT just released this update: "Responding agencies continue to investigate the situation. The scene is outside of Building 32 (Stata) and 76 (Koch) near Vassar and Main Streets. Injuries have been reported. The situation is still very active and we ask everyone to stay inside."