A sheriff’s official said deputies were investigating Thursday morning after a vague threat referencing Lakewood High School was posted on social media, but the school was operating normally.

The school sent out a message to families around 7:25 a.m. saying it was safe to come to campus, Long Beach Unified School District spokesman Chris Eftychiou said.

Sheriff’s Sgt. John Finney said he didn’t know exactly what the social media post said, but, “I know it was a pretty veiled threat—not specific.”

A screenshot, which was apparently from Snapchat but being passed around Facebook Thursday morning, referenced Lakewood High and warned people not to go to school.

It also included a list of first names and said, “If I don’t seem happy to be there or never smile it’s probably the [expletives] in the school.”

After looking into it, law enforcement decided the threat wasn’t credible, Eftychiou said.