About 50 firefighters continued to fight a fire in an abandoned Auckland freezing works on Saturday.
The building is often used as shelter by homeless people but no-one is reported to be injured.
The Fire Service says the fire is now under control, and they are focusing on dampening down hotspots.
A fire commander says they hope to have the blaze completely extinguished by Monday.
The Waitemata Area Commander, Dennis O'Donoghue, says the flames are out, but there is still a lot of smoke as the fire burns underneath the collapsed buildings.
Mr O'Donoghue says they have diggers lifting the rubble so they can douse the flames and hope to have the site completely cleared by the start of the week.
The massive blaze at the old Southdown Freezing Works building on Hugo Johnston Drive in Penrose, took hold at about 8pm on Friday. At one stage about 120 fire crew were at the scene.
The Fire Service says the blaze spread 80 to 100 metres through a line of connected industrial buildings of up to three storeys.
Businesses near the blaze were evacuated and trains through the Southdown station were stopped. Train lines that pass through the area remained shut on Saturday.
Area Commander for Counties Manukau Kerry Gregory said homeless people were known to live in the derelict freezing works, but she's confident none were inside when the fire broke out.
Auckland Medical Officer of Health Andrew Lindsay says some of the buildings contained asbestos, but the health risk is low because winds have blown the smoke away from populated areas.
Also, he says, the high temperature of the fire is likely to have changed the asbestos fibres.
Despite the low risk, Mr Lindsay says people should avoid inhaling dust or debris from the fire.
The buildings were the scene of another major fire in 2008.