A fire in school grounds which has destroyed an outdoor classroom is being investigated by police.
Astley Park School in Chorley, Lancashire, for pupils with special educational needs said the blaze started at about 19:00 BST on Sunday.
It said the main school building was not damaged and the school would reopen as normal on Tuesday.
The school said an outbuilding and a container with play equipment were damaged in the blaze.
There are 145 pupils aged between four and 16.