Fontana police were searching Friday for the student behind a panic-inducing prank that sent students scrambling under their desks and prompted school officials to lock down Heritage Intermediate School after the warning "to get down" was heard on the public address system.
About 10:50 a.m., the Fontana Police Department received a call from a worried man who received a text from his daughter -- a sixth-grader at the school -- about a shooter on the campus. Her peers sent similar text messages to their parents.
The school immediately initiated a lockdown, although there were no signs of an active shooter on campus, a news release read.
Fontana police checked the campus with assistance from school staff. After the campus was cleared, authorities learned that an unknown student had gained access to the school's public address system, ordering students in all classes "to get down."
Late Friday, investigators were still trying to locate the student behind the prank.
Heritage Intermediate School serves students in grades sixth through eighth and is in the Etiwanda School District.