West Yorkshire Fire Service said half the building was on fire, and more than 50 firefighters are working to tackle to blaze at the Freeston Academy in Normanton, near Wakefield.
I was on my way home when I saw this massive smoke and flames.
There’s about 30 or 40 firefighters and police there.
They’ve turned us all away and stopped us all going up the street.
There’s loads of kids here waiting for their GCSE results and they’re all coming away in tears.
Ian Bitcon, area manager for safety at West Yorkshire Fire and Safety, told the Yorkshire Evening Post:
We were first call at 9.15am this morning and sent two fire engines. When they got here we had a quickly developing fire.
We have now got ten fire engines and an aerial appliance here.
Fires in the roof are always very difficult to deal with. Teams have worked really hard to deal with the incident so far.
It is almost extinguished but we expect to be here most of the day.