KEY POINTS:
A switchboard fault caused the fire that destroyed four Dargaville businesses.
Investigators finished a detailed search of the charred shop remains on Wednesday and pinpointed where the blaze started.
Fire safety officer Craig Bain said it started at the rear of Main Street Interiors, which the neighbouring Foster's Home Decorating and Resene Colourshop used for storage.
The business owners told investigators they had been having problems with fuses blowing and Mr Bain said that matched his findings.
"I found the remnants of a switchboard and the copper wiring had melted into blobs," he said. "If fuses keep popping at home or work it indicates there is something wrong and it's time to get an electrician to take a look."
Demolition of the four buildings and their removal has been complicated by the discovery of asbestos in some of the building's panels.
Yesterday the Kaipara District Council used hoses to wet down the site to prevent any particles of asbestos becoming airborne.
Because asbestos has been found, Department of Labour rules require the removal of the rubble to be supervised by a specialist.
The specialist and the demolition manager examined the area yesterday.
The removal of the rubble is expected to take three weeks.
About 100 firefighters were called to douse the blaze that started about 7.30pm on Monday.
- NORTHERN ADVOCATE
