The fire which broke out at Millais School in Horsham on Thursday 20 March is now being treated as a crime.
Both Police and Fire services carried out an extensive examination of the scene and indications are that the fire may have been started deliberately.
The school is working closely with police on the investigation and it’s likely that they will be at the school for several days.
No one was hurt in the fire, but local traffic was disrupted for a while in the evening rush hour.
If you know anything at all please call 101 quoting Operation Broadband or the independent charity Crimestoppers anonymously on 0800 555111.