A 17-year-old student at Lake Mary High School in Lake Mary, Fla., fatally shot herself at the school Wednesday morning.

Seminole County Sheriff Dennis Lemma says the student, a girl in 11th grade, died in the school’s auditorium building from a single gunshot just before 8 a.m. Authorities say the girl asked to be excused from class to use the restroom. and a few minutes later, a gunshot was heard.

School resource deputies and a nurse responded in “less than a minute” but could not save the girl.

Principal Mickey Reynolds and Seminole County School Superintendent Walt Griffin cancelled all Thursday classes at Lake Mary, as well as all athletic and extracurricular activities Wednesday and Thursday. Grief counselors were dispatched to the school and will be there again Thursday, even though classes won’t be in session.

Faculty members used their radios to report the gunshot, prompting a lockdown and response from resource deputies.

The lockdown was lifted before 8:30 a.m. and the campus had resumed normal operations, a district spokesman says.

Parents who wished to do so were allowed to pick up their students after the lockdown lifted. 

During the lockdown, the school sent a recorded message to parents stressing that the campus and its students were safe.