This is 99% invisible. I'm Roman Mars.

The story we're about to tell is pretty much the worst thing a parent can imagine.

We were awakened by the phone ringing. That's Noreen Gosh. It was early on a Sunday morning in 1982 in Des Moines, Iowa.

Noreen's son Johnny had left for his regular paper route.

It was the neighbor saying they did not receive their newspapers.

This wasn't like Johnny.

He'd been a paper boy for years.

He'd never missed a delivery.

His dad got up and said, I'll go help him finish the route. He's probably just running late.

He went up the street and that's where he saw Johnny's wagon sitting.

Johnny's red wagon was sitting at the corner.

It was still full of newspapers.

He rushed back and told me Johnny was gone and called the police. Johnny Gosh was gone and called the police.

Johnny Gosh was 13 when he disappeared.

He had blue eyes and dirty blonde hair with a small gap between his front teeth.

And his would be the first face of a missing child ever printed on a milk carton.

It's been 30 years since these milk cartons came and went.

I wasn't even alive to see them, but I still know about the faces on the milk cartons.

That's reporter, Annie Brown.

The image of a missing child on a milk carton became iconic, a kind of cultural shorthand for missing children.

And even though this image has stuck around for three decades,

the actual milk carton campaign only lasted two years,

...