A 12-year-old who attends Bonita Vista Middle School was arrested Tuesday in connection with sending threatening messages, Chula Vista police said.

The threat quickly spread on social media and caused fear and concern on several campuses in the Sweetwater Union High School District. Classrooms in the school district were almost empty as some parents decided to keep their children home.

The news spread to other campuses like Rancho del Rey Middle School. In a message sent to parents, staff and students at around 3:40 p.m. Tuesday, Ulisses Hernandez, the principal of Rancho del Rey Middle, debriefed the school threat, saying, in part:

“This morning, at about 6 am, community members notified the administration of a concern spreading on social media regarding a school threat to Rancho del Rey. The administration reported to the school ASAP and notified CVPD and SUHSD. At exactly 7:38 am, I sent out a Jupiter Message informing the Rancho community that the threats were not credible. Eventually, as the news spread, concerned parents requested their students check out of school for safety. We understand and respect the decisions made by parents who picked up their children. The staff worked collaboratively to support the parents with their requests. CVPD is investigating the source of the original threat made to multiple schools since yesterday. The threats do not pose an imminent danger to our students, and it is safe to continue with the regular school schedule.”