UPDATED: 12.07PM There looks to be nothing to salvage after a fire ripped through a technology block at an Auckland school.

Long Bay College is shut for the day after the destructive blaze early this morning.

It's understood students' work has been lost in the fire.

Almost 50 fire fighters and more than a dozen fire engines were called in around 2.30am.

The Fire Service communication team has tweeted there is nothing suspicious about the fire, and believe it was accidental. 

Area commander John Booth said it's done a lot of damage. 

"It's been a pretty intense fire and fire engines are going to be at the school for probably most of the day. The headmaster's decided to shut the school down."

Mr Booth said the fire is now under control, and they are dampening down the area. 

Principal Russell Brooke said the 1975 building's is full of smoke with huge amounts of water and damage.

"Big rooms, lots of equipment, lots of expensive equipment in there" he said.

It housed fashion rooms, commercial kitchens, engineering and wood shops.

Residents have described hearing the fire crackle, and being woken by the smell of smoke.

"Being such a massive event, it's going to have a huge impact on the community, there was a number of people out this morning who have been watching it unfold and no doubt a lot of residents were probably worried this morning that their houses were going to be involved" said local resident, Mark Baldwin.

New Zealand Herald reporter Ophelia Buckleton said the full extent of the damage is now clear to see.

"It totally ruined the building, the corrugated iron roof has completely caved inside, the windows [have been] blown out and all the grass along the front has been completely burnt. There's a real strong smell of smoke in the air as well here."

Year 13 student Byron Buys said he had had classes in the block for the last four years.

The 18 year old said the students had just about finished a big woodworks project, which had now been totally destroyed.

"I was brought up on that block. A lot of memories were built in there. It's scary to see how quickly it can disappear." 

A spokesperson for the school said they're not sure when students will be able to return.