A rumor that a student might bring a gun to school prompted a lockdown Tuesday morning at Niwot High School.

The lockdown started at around 9:26 a.m. and was downgraded to a lockout just after 10 a.m.

The Boulder County Sheriff's Office helped a school resource officer search the campus and review security camera footage.

The officers did not find any credible threat and gave an "all clear " around 10:45 a.m.

Deputies will remain on the campus as the school returns to normal operations.

Niwot High School is located at 8989 Niwot Road, and is part of the St. Vrain Valley School District.