By 8:30 p.m., one team turned back and landed safely. the other disappeared. >> the reminder to us that those who serve put themselves at risk both in training and in combat. >> reporter: in the helicopter that went missing, four national guardmen from louisiana, and seven marines from camp lejeune in north carolina. >> it is a very experienced unit. and one that has received numerous accolade from its service to our nation. >> reporter: witnesses on shore in navarre, florida, could hear it crash. >> the smell of fuel strong. >> reporter: visibility remains low. the u.s. military is calling th...