Naperville North High School was closed Wednesday because of an apparent bomb threat to the school.
The Naperville School District says the school was also closed for after school sports and activities while the Naperville Police Department conducted an investigation.
Students who had arrived at the school Wednesday morning were taken to Naperville Central High School to be picked up by families.
Several schools in the district were also placed on lockdown Wednesday for an external threat not related to the Naperville North High School Incident. The lockdown was lifted by the Naperville Police Department Wednesday afternoon.