A lockdown was implemented at Brentwood High School after the school received a threatening phone call with an intent to cause harm, according to a letter the district sent to parents.

Members of the school's security team were outside the school during student pickup and spoke with parents. District officials said Suffolk police implemented safety protocols to protect students and staff.

According to the district, a police investigation determined that the threat was not credible.

One parent said they received an email through ParentSquare about the lockdown and picked up their child about an hour after the school day had ended.

Students described a tense scene when the lockdown was first announced.

“After the announcement went off, which sounded very urgent, teachers started screaming at kids to get inside. Teachers were seriously worried. Eventually, everyone calmed down. I'm pretty sure it was over here where it happened. I was on the other side,” said sophomore Jade Council.

News 12 has reached out to police for additional information about the incident and is awaiting a response.