An entrance to Granger High School is seen on Wednesday, May 2, 2018.

The Granger School District was put on lockdown on Friday as officials investigated an anonymous threatening note at the high school, according to information from the district and the Granger Police Department.

The district went into a “secure and teach” lockdown at 10 a.m. No one was hurt.

Police and district officials interviewed several students, and identified the student wrote the note. The student was placed on emergency expulsion and taken into juvenile detention.

At that point, normal school operations resumed, police said.