Crooked Oak Schools went on lockdown Thursday morning due to a false alarm.
First responders were alerted of the lockdown and even heard there may have been a shooting.
However, officials quickly discovered a technical mistake had caused the panic.
"It's a new security system that we have. We're not quite sure what happened, but we do know that it was a false alarm," Superintendent Bradley Richards said.
Richards said a staff member likely typed a wrong number into a phone, triggering the intruder alert throughout campus.
Coincidentally, a student was arrested for an alleged threat at the same school Wednesday.
"They located the 16-year-old student who made this threats allegedly, and took him into custody," Oklahoma City Police Sgt. Megan Morgan said.
Richards said parents were alerted to both incidents, and class is back to normal.
The district is looking into their new automated system and how to prevent a scare like this again.