Gunfire at a reno hospital complex. The crisis over, the questions just beginning. Later some answers to the question so many people have about the report that take a multivitamin and other supplements not only wont help you but could actually even hurt you. Well talk about that. We begin with the breaking news. Deadliest single incident for americans in afghanistan since the summer is of last year. A blackhawk helicopter down. 6 u. S. Members, natoled Security Assistance force are dead. It happened today in southern afghanistan, even though we dont yet have a full picture of what happened exactly, its beginning to come into focus. Barbara starr is working her sources at the pentagon joins us now. What are you learning, barbara . Reporter good evening, anderson. At this hour military investigators are urgently trying to figure out what did happen here. The reports are that the helicopter, the blackhawk, went down due to mechanical failure. But once it hit the ground, were any of those