Boston authorities suspended all mass transit and urged people to stay indoors Friday as they searched for the second of two suspects in the Boston Marathon boming Monday. The first suspect was killed in a shootout overnight.
This image provided by the Boston Regional Intelligence Center shows Dzhokhar A. Tsarnaev, identified by the FBI as suspect number 2, in the Boston Marathon bombings. Authorities say Tsarnaev is still at large after he and another suspect � both identified to The Associated Press as coming from the Russian region near Chechnya � killed an MIT police officer, injured a transit officer in a firefight and threw explosive devices at police during their getaway attempt in a long night of violence into the early hours of Friday, April 19, 2013. The second suspect, who has not yet been identified, was killed in a shootout with police. (AP Photo/Boston Regional Intelligence Center)