They never knew his name or saw that angelic-looking face. But their parents would never forget it.
For some, their caution was simply a result of what they read in news reports. Others, including Jim Stratton, had an immediate and very personal reason to be afraid.
"It sent a chill through everybody," said Mr. Stratton, whose son was in the same neighborhood play group as Etan Patz, the 6-year-old who never boarded his school bus on May 25, 1979. "You could not leave your child for a minute. Anywhere. It was like a dark cloud had come over the neighborhood."
Before Etan disappeared, the notion that a child could be abducted right off the street, in broad daylight, was not familiar. Children roamed their hometowns freely, unencumbered by fear. They could walk to school and the bus stop and just about anywhere they pleased all by themselves. That all changed after Etan set off for school in his favorite pilot's cap and corduroy jacket and did not return.
"In many ways, it was the end of an era of innocence," said Ernie Allen, president of the National Center for Exploited and Missing Children. "And parents suddenly became much more protective and much more hovering over their children."
Etan was one of the first missing children whose face would appear on a milk carton. In the coming years more faces would follow, mutely appealing for help from a public that began, for the first time, to mobilize on a grand scale in its efforts to find them. Even now, after more than 30 years, we still haven't given up hope for a resolution, for answers to every parent's worst nightmare.
Last week, authorities began ripping up an old basement near Etan's SoHo loft with the aim of finding his remains, spurred on by a cadaver-sniffing dog that picked up a scent there.
"He was here the whole time for all of us," said Cass Collins, Stratton's wife. "He was always in our thoughts."
The ones who never made it home are painfully seared in the nation's collective memory. There was 6-year-old Adam Walsh, kidnapped and killed in 1981 when he wandered away from his mother at a department store in Hollywood, Fla.
"There were some kids who biked around with a switchblade in their basket after it happened," said Alison Feigh, who grew up with Jacob Wetterling and sat next to him in sixth-grade math class. "There was a change of our innocence at that time. In sixth grade, I didn't even have the word abduction – that wasn't even part of my vocabulary."
Now a program coordinator for the Jacob Wetterling Resource Center, which teaches parents and children how to build safer communities, Ms. Feigh is fighting for a world in which children can explore beyond the edge of their driveways in this era of helicopter parenting.
"We want kids to walk around smart and not scared," she said.
But how to shake the fear? Ms. Collins, a writer, has two grown sons, one of whom was a rather anxious kid, often fretting about venturing off on his own, she said. Last week, when she read about the renewed search for Etan and felt that old familiar gut punch, Collins decided to apologize to her son.
"I said to him, 'If you got a sense from us that the world is a scary place, it came from Etan Patz,'" she said, her voice choked with tears. "That's where it came from. And I'm sorry if we did do that. Because it's not a good thing to imbue in a child."
Yukie Ohta was 10 years old when Etan disappeared from SoHo, where she grew up. They used to play in the same basement that is now being torn up by investigators. She remembers making necklaces out of dry macaroni down there. And she vividly recalls the search for her playmate that went on for weeks.
The posters, the neighborhood meetings, the milk cartons. The police officers knocking on her door.
"I would never let my child take the bus alone at age 8 or 10, but we all did when we were kids," Ms. Ohta said. "I think it was just a different time and place."
Ohta's mother brought her up with the rose-colored idea that Etan was still out there somewhere, alive. She has clung to this story, all the while knowing it was probably not true.
"That idea sort of has been shattered," she said last week after the latest search for his remains began. "And it's a little hard to take. You try to cope with something the best you can. And if you don't know, you can make up stories."
With each lost child came improvements in the way law enforcement agencies handle reports of missing children. In 1982, Congress passed the Missing Children Act, which established a toll-free missing children's hotline. Two years later, the National Center for Exploited and Missing Children came into existence.
After 9-year-old Amber Hagerman was abducted and murdered in Arlington, Tex., in 1996, the Amber Alert was created to broadcast news of a missing child through radio and television stations and on billboards.
These are just a few of the many protections enacted throughout the years. As a result, experts say, it's never been safer to be a child growing up in America.
Try telling that to parents like Jodi Halkin, of Palm Beach, Fla., who grew up around the corner from Adam Walsh. The mall where he was abducted stood across the street from her father's office. Halkin won't even write her children's names on their T-shirts or backpacks out of fear that a stranger might be able to call one of them by name.
"Though I realize that the likelihood of any one of my own three children being abducted is likely less than them being struck by lightning," she wrote in an email, "that doesn't mean that it's not a real, albeit slightly irrational, fear."