Still no word on what caused Lambton OPP to put schools in Petrolia on lock down. 
Students were ordered to stay indoors over the lunch hour yesterday after an incident in the area.
The Lambton Kent District School Board posted an online letter on its schools websites, explaining the situation to parents, and says there was never any concern for student safety inside the schools.
“At approximately 10 a.m., Lambton OPP notified our school regarding an incident involving police outside the school. There was is no concern for students’ safety inside the school during this time; however, as a precautionary measure Lambton OPP advised school staff to secure students inside the building until the situation was resolved.”
We’ll have more details as they become available.