Helicopter crews film thick flames and black smoke from a Wairau Valley business on Auckland's North Shore.
Chemical runoff from the fire on Auckland’s North Shore has polluted waterways, leaving three beaches off limits.
Fire crews remain at the Wairau Valley recycling plant after battling the blaze overnight.
The recycling charity is “heartbroken” by the damage but grateful no one was hurt.
Two workers fought a fire that ignited in a North Shore recycling plant and thought they had it under control until it “started exploding”.
The huge fire last night sent flames leaping into the night and plumes of toxic smoke across the city, triggering a massive emergency service response.
Fire and Emergency New Zealand said today the fire may have been caused by lithium batteries.
Chemical runoff from the monster blaze has polluted waterways and leaving three beaches off limits.
Firefighters in Wairau Valley battle the huge blaze - locals were told to avoid the area and close all doors and windows. Photo / Caleb Timms
“The emergency message alert advising people to stay inside was lifted during the night.”
He said an investigation was under way into the cause of the fire and crews are expected to remain on the scene until later this afternoon.
The Herald also understands two workers inside the building when the blaze ignited thought they almost had the fire under control, but then it “started exploding”.
A Herald reporter at the scene today said recycling rubbish was strewn around the building and Hillside Rd, which is closed to cars.
Firefighters were still extinguishing hot spots. A ladder appliance is shooting water over the rubbish and remains of the building, alongside two large diggers moving rubble around.
The “pungent” smell of burnt metal was still prominent in the air, she said.
A brief heavy rain downpour may have assisted efforts to dampen hot spots, but light gusts of winds are causing the smell of burnt debris to travel across the Wairau and Glenfield area.
Bystanders and locals have been taking videos and photos of the aftermath.
Firefighters battle the huge industrial fire on Auckland's North Shore. Photo / Dean Purcell
Auckland Council said residents close to the fire should still keep their windows and doors closed until the smoke and fumes completely disappeared.
“The council is monitoring the site closely and will conduct a thorough investigation.”