A spokesperson for the Los Angeles Police Department said the call was received shortly before 7:30 a.m. Details of the threat were not immediately disclosed.
Update: Sylmar HS has been taken off of lockdown. Perimeter has been lifted. LASPD will remain onscene conducting an investigation.
— LA School Police (@LASchoolPolice) January 22, 2020
More than a dozen LAPD vehicles were seen in the parking lot and at surrounding intersections as officers conducted a sweep of the campus at 13050 Borden Avenue.
The lockdown was lifted before 9 a.m. after investigators determined the threat was unsubstantiated, the LAPD said.