POMONA — Officials placed Diamond Ranch High School on lockdown Friday morning after the school received a threatening phone call, Los Angeles County sheriff’s officials said.

The incident began around 9 a.m. at the high school, 100 Diamond Ranch Road, Los Angeles County sheriff’s Sgt. Al Fulkerson said.
The school was notified by the Los Angeles County Sheriff’s Department regarding the threat shortly before the 9 a.m. beginning of the school day, Pomona Valley Unified School District Superintendent Richard Martinez said. The school had a late start schedule Friday — the last day of classes prior to winter break — for final exams.
Information was still being gathered, however Martinez said it initially appeared administrators received a “very general” threat against Diamond Ranch High School. The superintendent said he did not believe the threat made mention of any specific act of violence.
“The students are safe,” he said, adding that the campus lockdown was a “precautionary measure.”
Sheriff’s spokeswoman Nicole Nishida said administrators had received “perceived threat” against the school and the campus, but declined to give further details.
Students who had already made it to campus by about 9:05 were kept inside classrooms, which were in constant communication with the school office, Martinez said.
Students were showed up later were turned around and told to head home for the time being.
It was not immediately clear how many of Diamond Ranch High School’s 1950 or so students were on campus during the lockdown.
In the meantime, he said, officials were making preparations, such as arranging for lunch, in case the situation continued long-term.
Between 20 and 30 deputies remained at the school shortly before noon, Nishida said. The deputies joined school officials going room-to-room through the campus.
“This is protocol,” Nishida said. “Once it goes into lockdown, want to make sure everyone’s safe in every classroom.”
Once finished with the campus search, the lockdown was lifted at about 12:45 p.m., Nishida added.
Parents were notified of the lockdown via an automated phone call, and would be notified via phone and through the school’s website once the lockdown was lifted, Martinez said.
Xavier Navarro, 38, of Pomona, waited outside the campus to pick up his son, an 11th-grader.
“Once I get him, I’m just going to hug him and take him home,” the father said.
He said the situation appeared to be under control, though he was very worried during the first hour of the lockdown, when he said he and other parents had no information about what was taking place at the school.
“I’ve never been this scared in my life,” Navarro said.
After dropping his son off Friday morning, the father said he returned to the school after learning of a situation at the campus.
In the wake of the recent tragic shooting in Newtown Connecticut, Navarro said school security should be a top priority, “Even if it means an armed guard at every school.”

Staff photo by Watchara Phomicinda