Highfield Humanities College suffered ‘significant water damage’ after an arson attack set off the sprinkler system.
Firefighters were called to the school when an automatic fire alarm went off at around 10.55am today.
White watch manager from Shore Shore fire station, Steve Boyne, said a toilet roll dispenser in a second floor boy’s toilet was set alight.
Staff evacuated the building and nobody was hurt in the incident, which is now being investigated by police.
Mr Boyne said: “The cubicle has heat and smoke damage, the toilet roll dispenser was destroyed, and there is a significant amount of water damage.
“The fire service did great work in reducing the amount of water damage by reducing the flow of the sprinklers.
“The fire was put out extremely quickly by the sprinkler system, nobody was hurt, and the students are safe.”
The school, in Highfield Road, South Shore, said on its website: “To ensure the safety of all pupils, staff, and visitors, we have taken the decision to close the school.
“All pupils were asked to ensure arrangements were in place for this before they were dismissed.
“We will post more information as soon as it is available.”
Mr Boyne said firefighters responded to an automatic fire alarm and were met by the school’s caretaker, who told them someone had started a fire inside the toilet.
The blaze comes just weeks after education watchdog Ofsted described Highfield as ‘at times unsafe’ for pupils to attend because of bad behaviour.
The last high school under local authority control – set to become an academy under the control of Tauheedul Education Trust in a matter of weeks – remained in special measures after inspectors became so concerned about pupils’ behaviour they ordered senior teachers to write an action plan before their visit was over.
Inspectors saw students running through the school’s atrium, leaving scattered tables and chairs, were told by pupils fights regularly break out, and spoke to parents and teachers who also expressed concern about poor behaviour from a small group of unruly students.
In his report, inspector Patrick Geraghty said: “An unpredictable and over-boisterous atmosphere was evident. The behaviour of a significant minority of pupils is unacceptable.”
Ofsted’s visit came days after teachers called in police when up to 200 were described as out of control after a spat between two schoolboys led to a crowd of students chasing each other.
But inspectors also found there is ‘some good teaching’ and the majority of youngsters want to do well in class, showing ‘a palpable desire’ and expressing ‘an energy and ambition for betting learning’.
Headteacher Lynette Norris said previously: “Everyone at the school is striving to address these as quickly as possible to ensure all students have the opportunity to reach their potential.
“School improvement does not happen overnight and there is still much work to do. We are taking robust action to improve behaviour.”