Palatine High School was placed under a hard lockdown -- and two nearby elementary schools were also locked down -- after a threat at the high school shortly before noon Friday, Palatine Township Elementary District 15 announced Friday night.
Police responded immediately to search Palatine High with the school staff and ruled out any danger.
As a precaution, the nearby Virginia Lake and Jane Addams elementary schools were told they should also go into a lockdown.
The lockdown at Palatine High School was called off shortly after, and the high school used the incident as a safety drill. The lockdowns soon were lifted at the elementary schools as well, and normal routines resumed.