Police said a call came in around 5 p.m. about a man seen entering the school with a gun.
School officials said security cameras were able to determine it was an NHS JROTC student with a plastic drill replica.
"You don't know where a potential threat might be and our school rooms are safe and made of concrete walls and enclosed doors and things like that," said Chip Sudderth of Durham Public Schools. "You want to get students into a safe place and be very careful and thoughtful about getting them out to a safe place."
Students, teachers, coaches and parents are waiting across the street from Northern HS as @DurhamPoliceNC and @DurhamSheriff sweep the school. Some students said they had to run off the football field when lockdown was called. #abc11 pic.twitter.com/tqV3uRb4mj— Josh Chapin (@JoshChapinABC11) October 15, 2019
Students at the school for extracurricular activities were sheltered in place and were released to their families at North Carolina Korean Church across the street.
"We are enormously grateful for two things: one it wasn't a real threat and two that our law enforcement-the sheriff's department, the police department, they were so professional," said Sudderth. "They came and took care of our kids as if it were an actual threat."
Nikki Warren ran to pick up her 17-year-old after she texted her at 5 p.m.
"My child doesn't find it funny and none of the kids I deal with find it funny so it's not a joke," said Warren. "This world is crazy so I came to get my child."
ALERT!— Durham Public Schools (@DurhamPublicSch) October 15, 2019
Law enforcement is investigating an UNCONFIRMED report of a person with a weapon on the NHS campus. Students and staff are sheltering in place as precaution. @KnightsNHS