Authorities received a 911 call at 8:20 a.m. Thursday regarding a threatening note left by a male student. Students were immediately locked down in their classrooms. As certain areas of the school were cleared by deputies, students in those areas were placed outside, officials said.
A short time later, the 16-year-old student, believed to have written the note, was found dead on a nearby railroad tracks. Investigators said he committed suicide by stepping in front of an oncoming passenger train.
Just after 11 a.m., officials announced that students were being released from school for the day. Parents have been notified that school is closed for the day.
It was unclear what the threatening note said, but the Ventura County Sheriff's Department stated that it was a "threat of harm," not a shooting threat.
Moorpark High School was expected to resume classes Friday. School officials said grief counselors will available for students and faculty members.
Arroyo West and Mountain Meadow Elementary schools were placed on lockdown as a precaution, but those lockdowns have since been lifted. Both schools have resumed normal operations, the sheriff's department said.