BAGHDAD, Iraq - Shortly after a roadside bomb killed a U.S. Marine in a western Iraqi town, American troops went into nearby houses and shot dead 15 members of two families, including a 3-year-old-girl, residents say. The military is investigating possible misconduct by the Marines and confirms there is a video, which Time Magazine says shows the aftermath of the Marines' assault. Residents contacted by The Associated Press described what happened after the Nov. 19 roadside bomb in the town of Haditha, 140 miles northwest of Baghdad, as "a massacre." Khaled Ahmed Rsayef, whose brother and six other members of...