>>> this is flo unger. and she was a student from 1975 to 1978. >> the tragic death of florence unger, the mother of two young children, was a shock to coworkers, friends, and family. >> unless you've lived through it, it's very difficult to explain. you feel like your head's going to explode. it's total and complete devastation. there's nothing like it. it's unimaginable. >> police at the scene had to consider every possibility. >> do you have a suicide? do you have an accident? or do you have a homicide? >> florence's family ruled out suicide as a possibility. >> there's no way that she could have contemplated suicide for a number of reasons. number one, she would have never left her children parentless. >> an accident seemed like a distinct possibility. the railing on the deck outside the ungers' cabin was freshly broken. it looked as if she were sitting or leaning on it and it gave way, causing her to fall to the boat launch below. but how did the body get into the water? mark unger hired a private indep