An investigation into the fire which destroyed four classrooms in a Christchurch school indicates the cause was accidental.
Fire and Emergency fire risk management officer Wayne Hamilton said investigators finished at Russley School at around midday today.
He said the team, which included an electrical engineer, suspect the fire was caused by a faulty electrical multi-box.
The early morning blaze yesterday gutted a block of four classrooms used by 120 pupils in the final two years of primary school. They lost all their year's work in the blaze.
The school said due to asbestos contamination the school site is still unsafe to access and will remain closed until it has been given an assurance by health and safety inspectors.
The school will be closed until at least next Tuesday.
It's likely the 120 children who now no longer have a classroom will be taught in the school hall while a rebuild takes place.