Fire crews from Invercargill, Wallacetown and Kingswell were called to an an alarm activation at an industrial building occupied by Growing Products in Matheson Rd, Kennington, about 8.05am on January 23.
Firefighters used breathing apparatus while tackling the fire and — as between one and five tonnes of asbestos were present — they required decontamination afterwards.
Fire and Emergency New Zealand undertook an investigation into the cause of the fire, which involved talking to witnesses, CCTV footage being obtained and a scene examination.
The fire happened in a shed used to manufacture soil products, the investigator’s report said.
Other connected buildings were not damaged in the blaze.
When the fire started the sprinkler system activated, but it was not very effective because the blaze began above it in the roof.
Prior to the fire igniting, maintenance staff had been working on a product bin using a grinder.
CCTV footage showed sparks hitting the roof, up to five metres above where they had been working.
As peat processing creates a fine dust which settles on everything, staff typically cleaned equipment between working on different products using compressed air, which resulted in the presence of dust clouds in the building.
The footage showed such a blow-down was conducted after the grinder was used.
Subsequently a worker saw a flash in the room and discovered the fire.
While staff attempted to extinguish the blaze using two hoses, they were unable to reach it.
Ultimately, the fire was classified as accidental, due to carelessness, with a high degree of certainty, the investigator’s report said.
