Firefighters will maintain a "significant presence" overnight at the scene of a fire in a South Auckland car yard.
Crews from across the region raced to the scene just after 3pm this afternoon.
The Papakura car yard was well-involved in fire when crews arrived, but it rapidly grew in size to about 110 metres by 80m.
Both cars and buildings on site were engulfed in flames, sending smoke billowing across the area.
Tyres could be heard exploding from the heat of the fire, while entire stacks of cars were consumed.
The fire led to several roads being closed, while residents nearby were told to shut windows and doors, as well as turn off any heat pumps, to avoid smoke entering their properties.
Shortly before 6pm, an emergency alert was sent to phones in the area advising residents southeast and up to 1 kilometre down wind of Parker St to close their windows and doors due to the smoke. This was lifted about 9pm.
Fire and Emergency NZ (FENZ) said about 9pm the fire was under control, with crews "overhauling" it and one crew remaining at the scene this morning.
This involves checking for hotspots and extinguishing any potential spot fires as they arise, FENZ said.
A fire investigator will begin the probe into the cause of the fire this morning.
Auckland Regional Public Health Service's (ARPHS) medical officer of health earlier said it was expected scrap metal, car parts, tyres, petrol, oil and other possible pollutants to be involved.
If anyone experiences any acute effects from the fire, such as difficulties breathing, wheezing, coughing or chest pain, they should seek assistance from their usual, or after hours, health care provider.
People can also free phone Healthline on 0800 611 116. Healthline is a free, 24/7 service with interpreters available.
Surrounding streets have reopened to traffic this morning.