In an email sent to families of Shadow Ridge High School, district officials said the campus was placed on secure status at the request of police, who asked for a brief lockdown while they investigated the reported threat. The lockdown was requested in the morning, and the school remained on secure status as of the district's message to parents.

Officials said the threat appears to be unsubstantiated at this time, though police continue to investigate. Students remained safe in their classrooms throughout the incident, and no one was allowed to enter or leave the building while the secure status was in effect.

The district did not provide further details about the nature of the reported threat or how it was received. It was not immediately clear whether the lockdown had been lifted by Tuesday afternoon.

Lockdowns and secure-campus statuses have become familiar procedures at schools across the Las Vegas Valley in recent years, as districts and law enforcement respond to reports of potential threats—many of which turn out to be unfounded. The Clark County School District, the nation's fifth-largest, has faced scrutiny over its handling of school safety communications in the past, with parents often learning of incidents through social media before official notices arrive.

Tuesday's incident at Shadow Ridge unfolded without reported injuries, and district officials emphasized that the campus remained secure while police conducted their investigation. The district's email to families did not indicate whether any arrests had been made or whether any specific individual had been identified in connection with the report.

This is a developing story. Anyone with information about the reported threat is urged to contact local law enforcement or school district officials.