NEW: Boston Police Report One Suspect Dead

NEW: Boston Police Report One Suspect Dead

Boston Police Twitter Account: Per Commissioner Davis: One suspect deceased, 2nd suspect (white hat) at large & considered armed & dangerous. pic.twitter.com/yimpQUT0zB

Joint Law Enforcement Announcement

"The situation is grave."

Residents of Watertown,Waltham, Cambridge, Newton, Belmont, Alton, Brighton are instructed to shelter at home. 

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MBTA has been shut down. All bus and subway stations have been closed. People at subway and bus stations are asked to go home.

Residents are instructed to stay in their homes. Do not answer your doors unless there is a uniformed police officer at the door. Do not congregate outside. Do not go to public places. Businesses in area of 480 Arsenal St in Watertown closed until further notice. Employees are instructed to remain home.

"It is believed that these are the same two individuals who are responsible for the Boston Marathon bombings and the death of an MIT police officer."