Up next, a family vacation turns into a nightmare.

That's when I've seen a diva of a female line face down in the water.

And possible clues provide more questions than answers.

Either it was an accident, someone caused her death, or she killed herself.

Experts can't seem to agree on exactly what happened.

There is not one single eye witness to anything.

There are no confessions. There are no fingerprints.

Until groundbreaking science discovers the truth.

Method, opportunity, motive, and last person to see them alive.

Classic reasons for murder.

Every year, the younger families spent their vacation on the western shore of Lake Michigan

in a place called Watervale.

It's almost a sanctuary for them to go somewhere else in the state

where they can just forget about the rest of the world and reconnect with themselves and their families and their loved ones.

Florence worked as a bank loan officer.

Her husband, Mark, a mortgage broker, was also a well-known radio personality.

Mark Unger, editor of sports radio show and a lady in somewhat of a celebrity within a circle of friends.

Their vacation in 2003 was like most others.

The youngest checked into their cabin, had dinner, and Mark spent time with their two sons,

while Florence was outside for some fresh air.

Mark read a story to the boys, saying a song, put them to bed, kiss them good night,

and came back out to the deck and that Florence was not on the deck.

...