(MT. VERNON, IL) — For the third time in a week, a Jefferson County school has been evacuated due to a security threat. This time, Casey Middle School was evacuated before 11 a.m. Monday due to a bomb threat. At press time, authorities including the Mount Vernon Police Department are on scene to perform a safety walkthrough of the premises. No injuries are reported at this time. Parents of Casey students were encouraged to pick their children up at nearby Hall Early Childhood Center. Officials with Mt. Vernon District 80Schools indicated that other schools within their district were unaffected by the incident at Casey. We will provide more information as it becomes available.