We are here to protect public safety,” Boston Police Commissioner Ed Davis said in the morning, as the extraordinary lockdown was put in place.
– Authorities say one of two suspects in the Boston Marathon bombing is dead and a massive manhunt is under way for the other, who has been identified as 19-year-old Dzhokhar A. Tsarnaev. Boston is effectively shut down in the meantime: Residents of Boston, Watertown, Newton, Waltham, Belmont, Cambridge, and the Allston-Brighton neighborhoods of Boston were told to remain in their homes; mass transit has been halted; businesses were asked not to open; and the Boston Globe reports that at least 16 area colleges have canceled classes. What we know of what happened overnight, per the AP and the Washington Post: The Middlesex district attorney says the two men are suspected of killing an MIT police officer at the college last night after the officer responded to a disturbance, then stealing a car at gunpoint and later releasing its driver unharmed. (All just hours after police released photos of the bombing suspects.) Authorities say the suspects threw explosives from the car as police followed it into Watertown; witnesses reported hearing multiple gunshots and explosions at about 1am. A transit police officer was critically wounded. The suspects and police exchanged gunfire and one of the suspects was critically injured and later died at a hospital while the other escaped. Doctors at Boston's Beth Israel Deaconess Medical Center say they treated a man with a possible blast injury and multiple gunshot wounds. They wouldn't confirm that the patient, who came in with police, was the suspect in the black hat from marathon surveillance footage. Police say the suspect on loose is a "terrorist" who "came here to kill people." Governor Deval Patrick held a press conference with police this morning extending the shelter-in-place warning to all of Boston. "There is a massive manhunt underway," he assured reporters. "We've got every asset that we can possibly muster on the ground right now." Authorities have identified the MIT officer who was killed as 26-year-old Sean Collier of Somerville, according to the Boston Globe. The MBTA police officer who was injured has been identified as Richard H. Donohue.