Principals walked campuses, making sure no doors were left ajar or windows opened. Beaufort County School District officials reminded staff to close and lock classroom doors when class was in session.
Beaufort County schools officials tried Monday to reassure parents it is safe to send their children to class, three days after the shooting at an elementary school in Newtown, Conn.
And they reminded people that the security needed to protect students has long been in place.
"Out first and foremost focus is the safety of the children," Coosa Elementary principal Carmine Dillard said. "That is certainly a heightened focus right now."
The need for vigilance was highlighted Monday when a threat was discovered scrawled in a bathroom at Hilton Head Island High School. Principal Amanda O'Nan declined to describe the threat, except to say that it suggested a shooting -- not necessarily at school -- and that it did not target one person or one group.
O'Nan said Beaufort County sheriff's deputies were at the school shortly after the threat was discovered at 12:40 p.m. and stayed through the end of the school day. Teachers and administrators guarded hallways throughout the afternoon. The threat remains under investigation.
District protective services chief Chris Barrow said the threat at Hilton Head High was the only security issue Monday at Beaufort County public schools.
Barrow is confident about district security plans and said no new measures were put in place after Friday's shooting in Newtown, which left 26 people dead, including 20 children.
However, security measures could be reviewed in the wake of the Connecticut massacre as more information about the shooting is released. "I think it's important to constantly reassess them," Barrow said.
Some principals sent letters home with students detailing security at their schools, which include limiting access to the buildings.
Visitors must be buzzed in through one door at the front entrance and sign into the school using a photo ID. Visitors are either routed through school offices or greeted by a receptionist at the door before they can enter the main building. Barrow frequently audits these measures by donning a disguise and trying to get in other doors or otherwise attempting to slip into the school unseen.
Instructions for a variety of security threats are in each classroom, Barrow said. Every school has detailed plans -- down to designating an area where parents can pick up their children in an emergency.
Those plans have been reviewed and drills take place annually, including regular "table top drills," where administrators and staff lay out the chain of events that would take place should their school be threatened. Law enforcement and emergency responders helped make the plans and have copies of school floor plans and photos.
Beaufort Police Chief Matt Clancy said his officers are well-equipped for school emergencies. They've run drills in schools after hours, including at Beaufort High. A special operations team -- similar to a SWAT team -- has practiced responding to workplace or school violence, Clancy said.
"I've gone to Beaufort Middle School in uniform, and they've checked my ID, sometimes while apologizing," Clancy said. "But I'm glad they do it. It shows they're not lax about it."
Lt. Joe Babkiewicz of the Bluffton Police Department said the department plans a renewed focus on shooter training for years to come, which could include drills with faculty and school staff.
A few principals said they heard from parents thankful for the security measures at the schools. When Red Cedar Elementary opened four years ago, parents thought the then-new security measures were an annoyance.
" 'This is like Fort Knox.' If I heard it once, I heard it 30 times (back then)," principal Kathleen Corley said. "But one mom called on Friday, and she said, 'Thank you for locking things up like Fort Knox.' "