Fire crews had to be decontaminated after attending an explosive fire in a building clad with asbestos in the central North Island.
About 50 firefighters attended the blaze, which destroyed a disused depot on the outskirts of Mangakino at 3am on Sunday.
Because the building contained asbestos, which can cause cancer, Central Lakes assistant manager Hamish Smith said most of the firefighting was done from as far away as was practical.
Only the minimal number of firefighters ventured close and a helicopter was used.
Mr Smith said those who may have been in contact with asbestos went through a decontamination process and their clothing was sent away to be cleaned.
He said wet weather on Sunday will help prevent any residue becoming airborne.
However, the area surrounding the blaze will have to be decontaminated.