All entrances to the school were sealed off by police around 7 a.m. as students inside took to social media to explain what they were hearing.
Classes are going on as scheduled after a suspicious person forced Francis Howell High School and Francis Howell Middle School no a lockdown on Tuesday morning.
Teachers at Southwestern School District in Piasa, Illinois are once again teaching in caution after a threat was found at a middle school.
Wentzville Police say a situation is unfolding in a nearby neighborhood.
Union School and Lindenwood University were put on a brief lockdown Tuesday afternoon.
The Washington Missourian paper reports that the suspect was captured on a deck of a home near Holtgrewe Road, west of Pottery Road.
Parkway South High School, Southwest Middle School, Wren Hollow Elementary and Hanna Woods Elementary are currently not letting anyone leave or enter the schools as a precaution.
The prison will remain on lockdown until the investigation is complete.
A student found a threatening letter in a locker.
According to the districts website its just a precautionary measure.