Fire gutted a shipbuilder's premises in the suburb of Ellerslie on Tuesday evening.
The fire, in the single-storey Miller Moyes Seacraft building in Cawley Street, started about 6.30pm.
Fourteen fire appliances and more than 50 firefighters were needed to bring the fire under control.
Wayne Hyatt of the Fire Service in Takapuna says some crew members had to be decontaminated because of a small amount of asbestos found at the site.
He says no-one was injured, although one firefighter later fell ill and was taken to Auckland Hospital.
A hazardous chemicals unit was set up at the site and an Auckland Regional Council civil defence officer sent to the site because of risks posed to the residential area by toxic materials and chemicals.
The Fire Service received many calls about the fire, including from people who could see the smoke from the southern motorway.
It's not yet known how the fire started.