A woman was forced to quickly flee a fire that took hold in an industrial building in Auckland this afternoon.
Around 70 fire crew battled a "large and severe fire" at Argus Fire Protection in Onehunga.
Argus Fire Protection general manager Bryce Donaldson said one employee was doing administration work inside the building when the fire started.
"She noticed fire coming through the ceiling and [when] she left the building, basically the whole building was on fire within a minute," Donaldson said.
Donaldson said the woman got out safely and no one else was in the building.
He said the company was "devastated" but they had continuity plans in place to get through the incident, adding they'd be back up and running on Tuesday.
"This is the main head office, we've got five other branches as well we can work from," Donaldson said.
"As the general manager of the company, it's devastating and it's something we don't sort of expect in our own building.
Fire incident controller Murray Binning said the cause of the fire is unknown at this stage.
The blaze reached a fourth alarm, which means between 15 to 20 appliances arrived at the scene with approximately 60 to 70 crew members.
"It's a relatively large and severe fire, the initial crews did an excellent job in cutting the fire off," Binning said.
"We've deployed a couple of aerial appliances and we've also got crews inside on interior attack with hose lines," he said.
Dave Pene, who witnessed the fire take off, said after spotting the blaze he ran inside to get his wife to call the fire brigade.
"By the time I had came back out the glass [window] had blown out and away she went, she just roared," he said.
"Even before the appliances arrived she was hell out ... when the window blew out [the fire] just rushed out and this whole block started to blow out.
"Once she got a bit of air she was gone, like within 15 minutes [the Argus Protection building] roof started collapsing."
Pene's appliance was across the road and said fire crews arrived on the scene within minutes, "it was fantastic".
Not only did fire crews do an amazing job preventing the fire from spreading to the metal warehouse, but a fertiliser company is also located on the other side and Pene said if the fire had reached there the whole block would have gone up.
Dr Marewa Glover told the Herald she just drove past the fire and the smoke has gone from dark black to white and it looks as though it's under control.