investigators won t confirm the taliban s claim that it shot down a military chopper in the southern part of the country. seven american service men were killed. nbc news chief correspondent jim miklashevski has the latest. what do we know about this point? we have details about what happened in the helicopter crash that killed seven americans and four afghans, by the way, that were on the black hawk helicopter. among the serve americans killed, u.s. officials here and in afghanistan tell us that two of them were navy s.e.a.l.s and one was a navy explosive expert. in addition, those officials, gec again, both here and in afghanistan, say that helicopter had gone into a landing zone in kandahar province there in southern afghanistan to insert forces into an ongoing operation. and that they actually had to shoot their way in to that landing zone because it was hot. there was enemy gunfire, enemy activity in the area. and it was when the helicopter had taken off and was actually