A fire erupted on the upper floor of a hostel building at Ella Du Plessis High School on Wednesday morning.
The City of Windhoek's fire brigade successfully extinguished the flames.
Earlier this year, the students were moved from this building as it was declared unfit for habitation.
However, the building was used for storing such things as matrasses.
Carlo Louw, Head of Operations at the Windhoek Fire Brigade, says that the exact cause of the fire remains under investigation, with suspicion leaning towards an electrical fault.
Louw also pointed out that the building, due to its age, does not comply with modern fire safety standards.
The principal at Ella Du Plessies High School, Jakavaza Kavari, expressed disappointment over the inferno.
He says the school will arrange for psychologists and fire experts to speak to the learners.