Greenback School was locked down Tuesday morning after a student threatened another student with the potential use of a firearm, according to the Loudon County Sheriff's Office. At Tuesday's presstime, no charges had been filed. LCSO Lt. A.J. Yokley said the school went into lock down for about 30 minutes Tuesday morning after the student making the threat did not show up for classes. "It was not knowing where the student was and the extent of the threat we made sure all the students were safe by having the whole school locked down until we could figure out what was going on," Yokley said. Yokley said the school's resource officer received information about the threat Monday. Greenback School Principal Barbara Bradley said the school practiced a lock down Monday, but the practice was unrelated to Tuesday's events. "He never stepped foot on the campus today," Bradley said. "Really, it was nonthreatening. There was no one on campus threatening." Loudon County Director of Schools Jason Vance said midday Tuesday that he was confident students were safe. "Everyone is safe. We think that our kids are taken care of, and we think law enforcement was very quick to respond, and we think all is good. ... We think the statement that was made was an empty threat. We think everything is back to normal at this point," Vance said. Yokley said officers attempted to call the student's mother. When they could not contact her, officers were sent to the student's home where they made contact with the mother. "The student was actually in the woods walking around. His mother actually texted him and told him to come home. When he came home he was detained by officers and brought to the sheriff's office and then the lock down was released," Yokley said. Bradley said the student will be disciplined but did not outline what that would entail. "We have zero tolerance, so he will be disciplined, yes," she said.