Sheriff's officials said the lockdown was prompted as a precaution as investigators conducted a search near the campus. The lockdown was lifted after it was determined there was no threat.
Riverside County Sheriff's Dept. reported us clear and has lifted the Lockdown. They have deemed it safe for students to return to school. 1st period will start at 8am. pic.twitter.com/QCr3JstNQw— Norco High School (@NorcoHighSchool) September 18, 2018
The school was also placed on lockdown Monday due to a report of a possible threat made against the school. That lockdown was lifted in that incident after sheriff's officials cleared the campus.