The incident has sparked an urgent investigation into the safety of similar buildings erected under the federal government’s Building the Education Revolution.
Dozens of children were evacuated from St Christopher’s Catholic primary school in Panania after the ceiling crashed to the floor.
The metal and gyprock roof caved in not long after children had left the room.
“She [the librarian] saw a crack and went to the adjoining room and ushered the children out,” said a Catholic Education spokesman, Mark Rix. “She was very alert and astute.”
“We expect to send our children to school and they will be safe,” said one father, who did not want to be named. “They could have been killed. It is unacceptable.”
The library had only recently opened after a $ 2 million refurbishment under the BER scheme.
WorkCover has launched an investigation and the federal Department of Education, Employment and Workplace Relations has alerted other schools that have had buildings erected by the same contactor.
The original contractor responsible for the refurbishment went into liquidation last year.
Since the roof’s collapse, structural engineers had given the all-clear for students to return to adjoining classrooms, said Mr Rix. The library would remain closed while WorkCover investigated.
Mr Rix said two other Catholic schools which had buildings erected by the same company under the BER program have had them checked by structural engineers and they had been declared safe.
A spokesman for the department said it had warned other education authorities about the collapse and would inform them of WorkCover’s findings. He said a taskforce that examined the scheme rated the quality of Catholic sector BER buildings as among the highest in the country.