Yet another fire broke out at the former Kirklees College building last night - the 10th this year.
The blaze was on the first floor of the derelict building in New North Road.
Crews from five fire stations were sent to tackle the incident just before midnight last night.
The building has been hit by fire again and again this year - with four fires breaking out over five days last month.
The college deployed security patrols with dogs - but arsonists managed to break in on Tuesday night and set the building alight.
Some 30 firefighters spent five hours tackling out the flames.
Fire chiefs and college bosses held an urgent meeting on Wednesday to work out how to tackle the issue.
Kirklees College say they are taking advice from a specialist site security firm.
Deputy principal Melanie Brooke said: “We remain extremely grateful for the help and support the fire and police services have provided in recent months.
“Everyone in our community continues to share our extreme concern, and disappointment, that their help continues to be needed despite best efforts from everyone to secure the site against this criminal activity.”