Erin Moriarty

The last time Heather Bish saw her little sister Molly was the morning of June 27, 2000, just before Molly left for her job as a lifeguard at Cummins Pond in Warren, Massachusetts.

Molly was playing with Heather's 11-month-old daughter, Michaela.

But shortly after Molly was dropped off, beachgoers arrived, and she wasn't there.

Police were eventually called to the scene.

By the time they told Maggie Bish, Molly had been missing for three hours.

And my mom was frantic on the phone.

She said, she's not there, she's not there, her shoes are there.

My heart dropped.

I just knew something was wrong because I knew Molly wouldn't go anywhere without her shoes on.

Why?

Because she didn't like icky feet.

When you first heard that she was missing, did you think maybe she had gone off with friends?

No.

John Jr.

is Molly Bish's brother.

Sixteen-year-old Molly was Maggie and John Bish's third and youngest child.

48 Hours interviewed John back in 2003.

Molly was an honor roll student, varsity athlete, and she had just completed her junior year of high school.

Molly was just very loud and fun.

Heather says despite their six-year age difference, they were extremely close.