Wantagh students have returned to classes after authorities evacuated the middle school and high school Thursday morning.
Superintendent Maureen Goldberg announced at 1 p.m. that an investigation by police had been completed and all students were returning to regularly scheduled classes.
After school and evening activities will go on as scheduled, Goldberg said.
The evacuation was prompted by a "threatening message" that was discovered in a boys' bathroom at Wantagh High School, Goldberg said in a statement.
Nassau County Police confirmed that at 9:26 a.m., school district officials alerted them to the threat.
Police said that they didn't believe the threat was credible but an evacuation was authorized as a precaution.
High school students and staff were sent to Forest Lake Elementary School. Middle school students and staff were evacuated to St. Francis Church.