Firefighters remain at a building destroyed in a massive inferno on Albany's North Shore last night.
Up to 18 fire crews from around Auckland worked late into the night to contain the blaze at the site on Triton Drive, in Rosedale, after it ripped through a building about 8.30pm.
Northern fire communications shift manager Colin Underdown said they had one crew at the site just after 5.30am today.
Made up of four firefighters, they are on standby to monitor for any hot spots, he said.
Video footage of the blaze show huge flames ripping through the building.
"There were some really loud bangs and the horrible smell of something electrical burning.
"It certainly went up very fast and it was well involved very quickly."
Exactly how the fire started is not yet known and a fire investigator is due at the scene this morning to determine the circumstances surrounding it.
Triton Drive, which was closed off last night, is now open.
Meanwhile, in Timaru, police are guarding what is said to be a suspicious fire south of the city.
Firefighters were sent to a blaze at a changing room block in Pareora just before midnight.
They found a 10m by 10m building "fully involved" in fire, authorities said.
Crews from Timaru and St Andrews were called in to help battle the blaze as a result.