Severe fires at two schools in the Black Country were started deliberately, police have said.
A blaze at Wilkinson Primary School, in Bilston, badly damaged the vast majority of the building.
And a derelict school building at the RSA Academy in Tipton has also been destroyed by fire.
Police said they were treating both fires separately, but were keeping an open mind as to whether they could be linked.
About 75 firefighters were at each incident after the alarm was raised on Monday evening.
Firefighters were called to Wilkinson Primary School, in Walter Road, at about 2145 BST and continued to damp down on Tuesday.
The school said on Tuesday that it would remain closed until after the October half-term break. It has not given a re-opening date yet.
Marc Webb, from Wolverhampton City Council, said: "Sadly, most of the school has been lost, around 80% of it, and it would be impossible for the 350 pupils to return to it in its current state.
"We're now making urgent arrangements to ensure there will be accommodation for the pupils to return to after half term.
"We are not sure yet what form this will take, and we're reviewing a range of options including offers from local schools and community organisations including St Martin's Church."
Police patrols have been increased in the area.
Insp John Scobbie, from Wolverhampton police, said: "This was a very serious incident and we are thankful that no-one was hurt.
"However, this fire has now destroyed the hard work of many pupils and teachers, who are now without a place to work and play."
Watch commander Nigel Walker, from West Midlands Fire Service, said: "There's severe damage to approximately 90% of the [Bilston] building.
"The remaining 10%, which I believe is the nursery, is also damaged by smoke and water."
Janet Garfield, who has two children at the Wilkinson school, said they were "completely devastated".
'Just a shell'
She said: "They were having the hall extended and that would have made it better for the children."
Speaking from the scene, BBC reporter Michelle Dawes said: "The nursery is fully standing but when you turn around, in front of you, what was the school, is now just a shell."
Fifteen fire engines were sent to the RSA Academy in the Bilston Road and Gospel Oak Road area in Tipton.
Crews were called to the building, measuring about 20m (65ft) by 100m (328ft), at about 1855 BST on Monday.
The fire, which was brought under control by about 2340 BST, also affected two other smaller adjoining derelict buildings.