Burning cooking oil in a wok sparked the fire which recently destroyed a sex shop in the Auckland suburb of Newmarket, the Fire Service says.
The Den Adult Concepts store on Khyber Pass Rd was gutted in the April 9 fire, which was started in a downstairs restaurant.
The blaze
led to a police helicopter, 18 fire trucks and about 80 firefighters from across Auckland converging on the scene .
Senior fire safety officer Roy Warren said a cook tried to put the burning wok out with blankets and a fire extinguisher, but was unsuccessful .
The fire spread from the wok to the ventilation duct above it, then through the adult shop and into the roof.
"We believe the ventilation duct had a layer of fat in it, which isn't unusual.
"We believe that caught on fire and when the steel duct got hot enough it set fire to the wood in the roof and down into the adult shop," Mr Warren said.
Little damage was visible from the outside of the adult store, but it was gutted inside, while the kitchen where the fire started suffered minor damage .
The Den Adults Concept store owner Adrian Jones watched his shop of 13 years get destroyed.
He was not able to salvage anything from the fire, and estimated he lost stock to be worth "hundreds of thousands", along with business in the months to come.
"But we'll be back," he said. "We've got three other shops and we'll be back in business in Newmarket, if not in this same spot then somewhere else.
"You get knocked down but you get up again."
A firefighter injured at the scene underwent surgery after a cut to his hand severed a tendon and another firefighter received a minor electric shock.
Newmarket Business Association general manager Cameron Brewer said it was the largest fire in Newmarket in recent history.
- NZPA
