It’s hard enough for adults to comprehend the magnitude of the horror that unfolded Friday at Sandy Hook Elementary School.

But how do you explain such evil to a child?

There’s no sense in trying to keep it from children, said Dr. Steven L. Dubovsky, chairman of psychiatry at the University at Buffalo’s School of Medicine.

“I would not shield them from it,” said Dubovsky, an expert on post-traumatic stress disorder who has done research on the 1999 Columbine shootings and interviewed some of the survivors of that Colorado rampage.

It’s inevitable that children will hear about it one way or another, and it’s best if they hear about it from their parents first, Dubovsky said.

It’s important to first and foremost emphasize that the child is safe and that nobody is going to hurt him or her, he said.

“What you would say is that a person went to [a] school and shot some kids and that was a very bad thing to do,” Dubovsky said. “You want to emphasize that it doesn’t mean you’re in danger."

And it’s OK for parents to show they’re upset by the events.

“They should see you upset, but not overwhelmed,” he said.

Children may ask why the parents weren’t there to protect the victims who were killed. “Make sure [your children] know: ‘We will protect you,’ ” he said.

Dubovsky strongly discouraged allowing children to watch TV coverage of the shootings.

“All they will show is how upset and scared everybody is and how traumatized they are,” he said. “It won’t help. It’ll just scare them.”

He said parents should also be cognizant that networks may break into regularly scheduled programming with news updates, he said.

Come Monday, he said that if your children seem fearful of going to school, it may be a good idea to take them to school.

“And maybe walk them in,” he said. “Make them feel you’re there with them.”

Later, after the initial shock of the incident has worn off, he said it may be helpful to come up with a safety plan with a child in case something like this should happen.

“Just like you tell your kids: Don’t talk to strangers,” he said.

Parents should talk to their kids about what they should do, where they should hide and other measures to stay safe.

Dubovsky recommended that teachers bring up the incident at school next week.

“Teachers should bring it up,” he said.

They should ask: “What have you heard? How are you feeling?”

Then, they should talk about the things that are being done to protect the children in school, such as keeping doors locked and other security measures.

Teachers should let children know that there’s nothing wrong with feeling scared and that the students can come to them to talk about their fears.

He also suggested drills specifically designed for such an attack.

“One thing we learned [from Columbine and other similar mass killings] is there are bad people in the world who come in all shapes and sizes,” he said. “There are bad people. The rest of us have to do our best to protect ourselves … and our children.”