Hold and secure lifted for Mayfield Secondary School and James Grieve Public School

(CALEDON, ON) - Members of the Caledon Detachment of the Ontario Provincial Police (OPP) are investigating a threats incident at Mayfield Secondary School.

On November 18, 2025, at approximately 7:00 am, officers received a report of a threat directed toward Mayfield Secondary School. Out of caution, Mayfield Secondary School and James Grieve Public School was placed into a hold and secure, which has since been lifted.

Investigators determined the source of the threat and have placed one youth in custody. The identity of the youth remains protected under the provisions of the Youth Criminal Justice Act (YCJA).