Monte Vista High School Briefly Locked Down Over Unverified Threat

DANVILLE (CBS SF) -- A high school in Danville was briefly placed on lockdown Monday following word of a threat on campus.

Police announced about 12:20 p.m. that Monte Vista High School had been placed on lockdown because of what it called an "unverified written threat."

In a letter to parents, principal Kevin Ahern said the action was prompted by anonymously written graffiti threatening school safety, and that students were told to shelter in place as a precaution.

By 12:39 p.m., police said the campus was searched and cleared, and the lockout order had been lifted.