A blackhawk helicopter down. 6 u. S. Members, natoled Security Assistance force are dead. It happened 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 six military members still alive . They are looking at a report that the helicopter once crashed came under mortar fire from Taliban Forces in the immediate vicinity. What they need to determine now, did the six members die in the crash, or is it possible, possible that they were alive when they hit the ground but there was a mortar attack and they perished in that . Investigators are talking to members of a