Parents at Clopper Mill Elementary School are alarmed after teachers let a second youngster wander off in the middle of the day.

The 9-year-old was missing for hours without anyone noticing. It wasn't until a police officer stumbled upon the child that the school realized anything was wrong.

Parents emailed WUSA9 this morning, worried about the situation here. A six-year-old was allowed to wander away from the school last year. Again a nine-year-old this week.

Some parents think the school needs to do much more to make sure it doesn't happen again.

“I'm still upset,” said the boy’s dad. “I'm worried.”

We’re not using his name to protect his son. He feels Clopper Mill's principal is trying to hush up a huge problem.

“When you drop your kid off, you expect to go back there and pick him up,” he said.

On Wednesday, facing some teasing from other boys, the fourth grader walked away from lunch, across three highways, at least one freeway on ramp, then over I-270. It took about three hours for him to cover the four miles to get back home.

“How many possibly bad people saw him before that?” asked his father.

A Good Samaritan noticed the 9-year-old alone outside his apartment and called 911. When a police officer found him and called the Germantown school, neither his teacher nor any other school official even knew he was missing.

“That morning could have been the last morning I ever saw him because you didn't take the time to verify his whereabouts,” his dad said.

Last year, the school had a nearly identical problem. Only then it was a 6-year-old, with a headache and a fever, who walked out of the school alone and headed to his day care.

“It's scary to know that it happened again,” that child’s stepfather said. “You lose all confidence in the school you're sending your kids too.”

The fourth grader's dad said his teacher knew he wasn't in class after lunch, but never tried to figure out why.

He said all she had to do was “pick up a walkie-talkie and say, ‘Hey….is no longer in my class.’”

Both times children went missing, the dads said school leaders promised it wouldn't happen again. But they've lost faith.

“I want to make sure this doesn't happen to anybody else's child, not just my own,” said the father of the fourth grader.

The principal declined to talk to WUSA9, but she promised to send over a statement.

The 9-year-old's dad said he is facing some punishment for wandering off. And he told him very clearly never to do it again.

But the dad just cannot understand why the school did not stop the child before he left -- or notice that he was gone.