I suspect the NTSB will look into to see if the pilot made any attempt at flight planning that day. A resident near the crash site said the fog was the worse he had seen it in the 17 years he lived there..
theres one video ive seen of another chopper hovering over the burning wreckage...not sure how long after the actual impact, but man, you literally cant see half way up the the surrounding hills and mountains...very dense fog