Boston Bombing Day 4 | The Firefight: 'I Thought We Were Gonna Die'

Law enforcement's desperate search for two young killers takes a dramatic, violent turn. Day 1: http://bit.ly/1TldQIe Day 2: http://bit.ly/1XKMH2J Day 3: http://bit.ly/1Tle9TB [This is the fourth of five installments of an ABC News digital special report "5 Days," which tells the hour-by-hour, day-by-day story of the investigation into the 2013 Boston Marathon bombing, with behind-the-scenes details based on interviews and evidence gathered by the FBI and Boston law enforcement agents who worked the investigation.} SUBSCRIBE to ABC NEWS:    / abcnews   Watch More on http://abcnews.go.com/ LIKE ABC News on FACEBOOK   / abcnews   FOLLOW ABC News on TWITTER:   / abc   GOOD MORNING AMERICA'S HOMEPAGE: https://gma.yahoo.com/