Parents, educators and students across the Washington region Monday morning will prepare for their familiar routines to start the week: Moms and dads packing lunches, children making their way to school, teachers settling into classrooms. But after the horrific massacre at Sandy Hook Elementary in Newtown, Conn., a “typical” Monday seemed unlikely, if not impossible.

For parents and schools staff, there is no way to avoid thoughts of the nightmare that unfolded Friday morning in an elementary school that could have been any elementary school, anywhere. Though an isolated incident, it was a reminder that unspeakable violence can shatter families, an entire community, with terrifying randomness.

Educators and psychological experts emphasized that maintaining a sense of normalcy at home and in schools should be a priority this week, particularly for the sake of young children who might feel anxious about returning to class.

“The important thing is to keep the routine,” said Georgetown University psychologist and childhood trauma expert Priscilla Dass-Brailsford. “Just making sure that children do go back to school is going to be important.”

Still, there will be evidence of the tragedy’s influence throughout the region’s school systems. Counselors and emergency response experts planned to circulate through area schools to help teachers and students process their thoughts and emotions about the shooting. Many campus flags will fly at half-staff. There will be moments of silence to remember the lives that were lost. Some local school systems said that they would heighten security for the week, with additional patrols and security personnel.

And in Fairfax County, police said cruisers will be stationed at every public school. Police emphasized that the additional police presence was not in response to a particular threat, but merely as a precaution.

Such powerful symbols, along with the presence of additional law enforcement personnel, are “a double-edged sword,” Dass-Brailsford said.

“I’m sure it will be very reassuring for the parents, but for the children and staff it’s going to be another reminder of what happened,” she said.

Kirsten Evans, PTA president at Westbriar Elementary School in Fairfax, said she has no reservations about sending her son, a third-grader, to school on Monday. She said she planned to talk to him about what happened in Connecticut before he goes back to class.

“You can never tell a child this is never going to happen, but what I’m going to tell him is that his teachers, those staff, everybody there, everybody is going to keep him as safe as they can,” Evans said, adding that she was profoundly moved by the heroic efforts teachers at Sandy Hook made to save lives. “I think our teachers would have done the same thing. As a community, we need to come together and really figure out ways to talk about this. We can’t hide it from our kids because, unfortunately, this is our world now.”

That world, for the time being, will include heightened security measures nearly everywhere. Schools officials throughout local jurisdictions reacted to Friday’s shooting with a flood of messages to their communities, expressing grief and reassuring families and staff that protocols are in place to help prevent such an incident here.

Public schools in Prince George’s and Loudoun counties plan to beef up security throughout the week. Dana Tofig, a Montgomery County Public Schools spokesman, said the school system would not comment specifically on security plans but said the schools would “do everything in our power to make our students feel safe and secure.”

Such safety procedures at local schools have evolved significantly in the past decade. After the Sept. 11, 2001, terrorist attacks — followed by the Beltway sniper attacks of October 2002 and fluctuating national terror alerts in subsequent years — many local school systems established more comprehensive protocols to shelter in place or implement total lockdowns. Now, with many examples of mass shootings in schools and elsewhere, many school systems have added “active shooter” drills to their emergency preparation training.

Tofig said Montgomery school personnel are well-rehearsed in emergency response measures.

“Staff and students know what to do if there’s an emergency,” he said. Such plans, he said, are “practiced on a regular basis.”

Briant Coleman, spokesman for Prince George’s County Public Schools, said the school system conducted an active-shooter training drill with local law enforcement in June. On Friday, D.C. Public Schools reminded principals to practice lockdown procedures and review active-shooter protocols. A representative of the D.C. Public Charter School Board said District charter schools plan to take advantage of active-shooter training for staff in coming months.

In Loudoun, public school officials plan to meet this week with local law enforcement agencies to review all school security procedures, according to the Loudoun County Sheriff’s Office.

Sheriff Mike Chapman reminded the community that school resource officers are stationed in all Loudoun middle and high schools, and Drug Abuse Resistance Education officers are also present at many elementary schools.

“We want to ensure that, together, we continue to do everything possible to ensure [the children’s] safety, and the safety of the entire school staff,” Chapman said in a statement.

After the Connecticut shooting, schools officials throughout the area also shared suggestions for parents about how to discuss the situation with their children.

Dass-Brailsford said that while it’s important to be honest with children, it’s also helpful to address the issue calmly, without too much emotion.

“In general, it’s really hard to explain violence to children,” she said. “Stating the facts is important, and keeping the emotion confined to reassurance — that they’re going to be okay.”

Lynn Main, principal at Lafayette Elementary School in the District, said in a message to the school community that teachers would not bring up the subject of the shooting unprompted.

“We do better working on the classroom level, following the children’s lead,” she wrote in the message. “We know some children may not know very much about what has occurred, and that is one reason we are working at a classroom level. We are very aware of how children process information like this at all the developmental levels . . . and will be sensitive to all our children.”

Alvin L. Crawley, interim superintendent of schools in Prince George’s, said all schools will observe a moment of silence at 10 a.m. Monday.

“Schools are safe havens for our children,” Crawley said in a statement. “As a society, we must come together to ensure that this type of callous incident does not happen again.”

Susie Livingood, a PTA president and parent of a third-grader at Dogwood Elementary in Fairfax, said she is confident that the schools have sufficient emergency-preparedness plans in place.

“I think it was, unfortunately, an incident that could happen anywhere . . . and you can’t always know when something like that’s going to happen,” Livingood said, referring to Newtown. “But I do feel confident that our school system can take measures.”

She has no hesi­ta­tion about her child returning to school.

“It’s a horrible tragedy,” Livingood said. “But I do feel that my son is safe at school, and that they do all they can to keep him safe.”

Valerie Strauss contributed to this report.