A classroom is unaccounted for in the school shooting in Newtown

Children clutching onto each other as they are hustled out of an elementary school. Parents weeping together in a school parking lot, police cars and ambulances flashing behind them. Police brandishing machine guns racing to a school.

While the images from Friday's school shooting in Newtown, Conn., will haunt many, it is children — those who attend elementary schools much like the one where 20 students and six adults were killed — who may be the most profoundly affected, experts say.

"Children are going to be shaken by this because it was at a school, a place that is supposed to be safe and comforting," said Dr. Patrick Kelly, a psychiatrist at the Johns Hopkins Children's Center. "There's something about this being at kindergarten that really hits people harder than some of the other school shootings we've seen."

Officials in three Baltimore-area school districts asked police to stop by schools Friday — particularly elementaries — to reassure teachers and students. In Anne Arundel, Baltimore and Carroll counties, officers checked in throughout the day, although there were no local safety concerns.

Baltimore County schools Superintendent Dallas Dance said he has asked his newly created Department of Safety and Security to evaluate the school system's crisis plans.

Dance created the office after several gun incidents at county schools this year. On the first day of school, a Perry Hall High School student wounded a classmate, 17-year-old Daniel Borowy.

Milton Borowy, Daniel's father, said he was "heartbroken" watching the news of the Connecticut shootings and was praying for the families.

"It very obviously brings back memories," he said.

Borowy said he doesn't believe stricter gun laws would solve the problem of school violence "because the criminals are going to get their guns anyway." Instead, he believes, the country needs to focus on basic morals.

"We live in a morally depressed society," he said. "It's become too easy to vent frustrations in the wrong way."

Daniel recently returned to school, according to his father, who said he would never forget his son's cries.

"It's an ongoing process, but he's alive. He's doing the things he loves to do," he said. "He still has nightmares. But as weird as it is to say, we're in much better shape than these people are."

Abby Beytin, president of the Teachers Association of Baltimore County, said the county is spending "an unbelievable amount of money" on school safety, such as police presence, metal-detecting wands and a full-time safety director.

"An awful lot of that is necessary because we still have not addressed the issue of common-sense gun laws," said Beytin, who taught kindergarten. "We have to have that dialogue, and it has to start now."

Local school systems run periodic drills in which teachers and administrators practice responding to crises — including a shooter in the school.

"Every school has a plan for what to do," said Charles Herndon, a Baltimore County schools spokesman.

Herndon pointed to the shooting at Perry Hall High as an incident in which the training paid off. Faculty members wrestled the gunman to the ground before more people could be injured.

In elementary schools, Herndon said, teachers and administrators must keep children safe while maintaining a friendly environment. "It's difficult to strike the balance between schools being safe and secure and them being warm and welcoming," he said.

According to news reports, the Connecticut gunman's mother worked at the school.

Many domestic tensions spill over into violence at schools, school safety expert Michael Dorn said, whether it's a noncustodial parent trying to abduct a child or a teacher being stalked by a former spouse. In those cases, schools can take steps to prevent that person from entering the school, said Dorn, executive director of Safe Havens International, a Georgia-based nonprofit organization.