The Escambia County Sheriff’s Office Ransom Middle School on Kingsfield Road was placed on a brief lockdown Thursday morning due to a written threat that was found in the school. Major Andrew Hobbs said surveillance video was being reviewed. Escambia County School District Deputy Superintendent Norm Ross said the lockdown only lasted about 15 minutes. The nature of the threat was not released by the school district or the Sheriff’s Office. Parents were notified by a telephone callout from the school.