The cost of the fire is tipped to reach $5 million, with the destruction of the hospitality kitchen, woodworking, textiles and metalworking rooms, a computer lab with 20 computers, and another classroom.

Many students lost projects they had been working on, and teachers lost years of teaching resources.

Police said it was too early to determine if the fire was deliberately lit.

It is the second fire at the school in as many years, with a blaze in the school’s canteen last year. It too is still under investigation.

Police did not yet know if the fires were linked.

They were quick however to quash unconfirmed reports within the community that there had been further fires in other areas of the school grounds, including one at the netball court canteen/toilet block. Fire brigade and education department officials also confirmed the reports were false.

The school remains without power and classes were moved to Berinba and Yass public schools and the Baptist Hall until at least tomorrow.

Police said they were on a routine patrol on Saturday when they came across the burning building at about 2.24am and alerted fire fighters.

Captain Allan Carey said when he arrived the building was well alight with flames coming from the roof.

He said it appeared to have started in the northern section of the building, near a power box. The fire then spread throughout the centre within 10 minutes of the initial alert.

Fire crews from Yass, Boorowa, Goulburn and the Rural Fire Service worked to save a demountable building behind the centre and the toilets and canteen block to the side of it.

“By the time we got here the whole building was on fire, it burnt very quickly,” Captain Carey said.

“When I saw the smoke coming from the highway, I knew it was going to be a big one.”

He said there was a lot of combustible equipment housed inside the building that would have accelerated the fire.

“Our main objective was to stop it spreading to other parts of the school.”

An excavator had to be called in to turn over large amounts of smoldering debris to help extinguish the fire. It was then used to demolish unstable walls of the burnt out building.

Fire fighters had the blaze under control by 3.30am and continued to mop up well past 11.30am.

More news from the Yass High fire inside.