An unannounced visit by three K-9 teams at the Red Oak High School Thursday resulted in a temporary lock down of the school, but no illegal substances were found. The teams searched the school building and parking lot. According to Red Oak Superintendent Terry Schmidt, there was no advance notice to parents or students the searches would be conducted. It wasn’t until the K-9 teams showed up that notices were sent to parents about the lockdown, to ease any fears they may have had by their children texting them about the lockdown.