"As they came in this morning, you could visibly see that they were quite shaken and affected by what happened over the weekend. One little girl came in and she said, 'you know, all I could do was think about how awful Friday was,' " says Heather Murray, a fourth grade teacher at Lincoln Elementary in Frederick.
Teachers at Frederick County Public Schools (FCPS) believe this tragedy may help the country realize how important their jobs are as educators and as students' first point of safety.
"We do reading and we do math, but at the end of the day, those children are entrusted to our care while they're here, so that's one of our number one priorities: To make sure that we're caring for those children as we would our own," says Murray.
School officials say security is something they're constantly talking about and everybody needs to know the plan.
"It's our procedures that protect us, the practicing of lock-down drills, the partial lock-down drills. Often our drills are in conjunction with law enforcement, with our emergency preparedness partners, we don't do this in a vacuum," says Clifton Cornwell, Chief Security Officer with FCPS.
Many schools may not be retro-fitted and designed differently, but classrooms are locked and entrances are more secure. At Lincoln Elementary you can't just walk into the school: First you have to buzz yourself in then walk through two sets of locked doors.
But some say it's not just procedures, it's being aware of people's mental health.
"Pay a little bit more attention to those who might have some sort of mental illness, maybe some who have experienced traumatic loss or a tragedy at some point recently or even in the past. Just pay a little bit more attention to them and be kind of on the lookout for signs that we might see with them," says Nikki Ramsay, School Counselor at Lincoln Elementary.
Nevertheless, safety will always be a school's top priority.
"Kids came to school happy, and that's what they need. I hope the school never becomes more than what it is, as a place for education, but it will also be a place where the adults in charge of the safety really need to know the plans," says Ann Reever, Principal of Lincoln Elementary.
There was an increased police presence at the start of the school day in Frederick, when many educators say students walked through the hallways much quieter than usual.