(KMOV) -- Marquette High School in Chesterfield, Missouri was placed on lock down after the school's intruder alarm was activated.
Just before 10 a.m. on Friday, police were called to Marquette High School to investigate.
Police went from room to room asking if anybody saw anything suspicious or saw anyone they did not recognize. According to Rockwood School District officials, everyone followed procedure by locking classrooms and entrances.
After investigating, police determined a student pulled the alarm and there was never any real threat.
Marquette school officials continue to investigate the instance to determine who pulled the alarm. If found, the student will face punishment as defined by the school's conduct code.