Fairfield police were called to investigate a threat to Notre Dame High School on Thursday, just after 1 p.m.
School officials said they received a threatening and violent call to the building.
The school went into lockdown, and police quickly responded to the area.
Officers said all students and staff were safe, and there was no active threat to the school or surrounding areas.
The call is believed to be a swatting incident and was not made from the immediate area, according to police.
Police said the lockdown was lifted, and all school operations resumed as scheduled.
Fairfield police say they’re still investigating the source of the phone call.