CHICAGO (CBS) — One person was in custody, after a false report of a person with a gun prompted a lockdown at Joliet Central High School on Wednesday.

Joliet Township High School District 204 said Joliet Central was locked down after receiving a report of someone with a gun entering the building. The district later announced the report was false, and the person who made the claim was in police custody.

The lockdown was lifted shortly after 10 a.m.

“At no time were students or staff in any danger. The school day will resume as normal. Thank you very much for your patience and cooperation. The safety and security of our students and staff is always our first priority,” the district told parents in an alert.