THIS STORY WILL BE UPDATED AS MORE DETAILS EMERGE

8:09 AM FOX News TV is reporting that the older suspect had shrapnel in his body when he died. Components of a pressure cooker were found at the scene of his death as well, they say.

7:46 AM The uncle of the two suspects has confirmed that the two suspects are brothers and are from the Russian region near Chechnya. They've been in the country for over a decade, he tells the AP.

7:38 AM CNN is reporting that police seem to be focusing on a single block in that Boston suburb where they believe the surviving suspect is cornered [CNN-TV report - no link available]. We are also learning more about the suspect, including the possibility that his brother may have received military training overseas. That is unconfirmed at this time.

6:56 AM The older  brother of the suspect currently on the loose has been identified as Tamerlan Tsarnaev, aged 26. He was a student at Bunker Hill Community College and studied engineering.

Police have killed one suspect in the Boston Marathon bombing and are on a manhunt for another in the Boston suburb of Watertown after an overnight car chase.

The two suspects attacked officers with explosives and gunfire before one was shot and taken to the hospital where he died. The other remains on the loose and much of Boston is on lockdown, with schools, businesses and transit systems shut down.

The man on the loose is believed to be 19-year-old Dzhokhar A. Tsarnaev, a Chechnyan. The suspects are reportedly brothers.

Boston Marathon Bombing Suspects | FBI.org

The two men reportedly robbed a 7-11 convenience store on the MIT campus in Cambridge shortly before 10:30 PM Thursday. Minutes later, police found an MIT campus police officer shot in his car. He later died at Massachusetts General Hospital. The suspects car-jacked a Mercedes SUV were pursued by police into Watertown where a shootout ensued. Police say the suspects threw explosives from the car as well.

At some point, one of the suspects was shot and the other fled in that SUV. The shot suspect was taken to Beth Israel Hospital where he later died. Police are currently combing the area and are concerned that the suspect at large may have more explosives.