'Looking into a furnace': Three injured in Auckland substation fire

Three people have been injured – one seriously – in a major fire at a Vector electrical substation in Auckland's Penrose.

Fire and Emergency NZ was alerted to the blaze on McNab St at 3.24pm and sent 12 crews, three aerial appliances and three special appliances to the scene.

Crews arrived to find the two-storey substation – measuring 20m by 40m – well ablaze and "endangering nearby warehouses".

"They are currently contacting the council and the owners of the neighbouring buildings," the spokesperson said.

Three injured as massive fire sends smoke billowing across Auckland - Watch on TVNZ+

Crews from Ellerslie, Onehunga, Ōtāhuhu, Remuera, Auckland City and Mount Wellington responded.

"There are reports of one person with burns."

Fire and Emergency Assistant District Commander Barry Thomas told 1News three Vector workers were carrying out maintenance at the facility when "there was an incident".

"It appeared to have possibly arced but Vector will have to comment on exactly what happened with their facility," he said.

Thomas said a "large plume of smoke was being generated" from the oil coolant of the transformers "and obviously that was blown across the Auckland motorway".

“As the wind changed, it started blowing in towards this commercial area and to some of the residents downwind.”

The fire had since been extinguished.

“At this point in time, we’re just trying to work with council around the runoff. There is oil that’s run off and it’s in the drains. It’s heading out into the harbour – we’re trying to mitigate that with Auckland Council.”

He expected power to be out for some affected properties “for a little while longer yet”.

The circumstances behind the cause of the blaze would be the subject of an investigation.

Hone St John was notified at 3.29pm and responded with two ambulances and one rapid response unit.

"Hato Hone St John treated three patients," a spokesperson said.

One person was taken to Middlemore Hospital in a serious condition, while two others in a moderate condition were taken to Auckland City Hospital.

Smoke was visible from the Southern Motorway and across the city, including Sylvia Park, the North Shore and East Auckland. Traffic backed up for several kilometres in both directions on the motorway.

Footage from the motorway showed flames and thick smoke from the building around 3.46pm.

A smoke advisory was issued by Fire and Emergency this afternoon.

"A building fire on McNab St, Penrose is creating a lot of smoke," Fire and Emergency said.

"Residents in the Penrose and Onehunga area are advised to close windows and doors."

Police said power outages were reported in parts of Penrose following the blaze "and some intersections are without power".

"Police units are assisting with traffic management at some intersections. Motorists, please take care on the roads."

The nearby suburb of Ellerslie was also hit with power outages.

A witness working nearby told 1News he saw lights flickering in the minutes leading up to the fire, followed by a loud bang – potentially from a tool dropping – before the power went out.

As the workers evacuated, the witness said they were met with a "wall of black smoke" as popping and cracking sounds could be heard.

"It was surreal – like it didn't feel real."

It was followed by "more extremely loud explosion-like bangs from the direction of the burning building".

The witness said they saw an injured person being treated by emergency services.

Robyn Michael and her husband John were driving onto the motorway at Ōtāhuhu when they saw black smoke billowing ahead of them, and were struck by just how dark it was.

"I've only seen black smoke like that from tyres burning," John told 1News.

As they drove past the site of the fire, they told 1News it was like "looking into a furnace".

"It was like a huge ball of flames, it was obviously a lot of heat being generated," Robyn said.

In a statement, a Vector spokesperson said 7000 customers were initially affected.

"Through network switching, we've already been able to restore power to approximately 3000 customers."

Emergency services were on site, and Vector crews were at the scene to "make the area safe".

"Our teams are working to restore power to customers as quickly and safely as possible."

Health NZ has issued a public health alert.

"Air around this location may be smoky. Health New Zealand advises that people who are sensitive to smoke, including those with heart or lung conditions, those who are pregnant, young children, and older adults, may experience symptoms such as coughing, shortness of breath, or irritation of the eyes, nose, and throat."

People affected by smoke were encouraged to keep their windows and doors closed; set air conditioning systems to recirculate or turn them off; keep pets indoors where possible and ensure they have clean food and water; check on others who may be vulnerable to smoke; and air out homes once conditions have improved.

A detour was in place for bus services on route 66 through Rockfield Rd, Main Highway and Penrose Rd, Auckland Transport said. Buses will not stop on Maurice Rd, Olive Rd, Penrose Station/Station Rd, 29 Station Rd, Penrose Station/Great South Rd and Prescott St.

"This may cause delays."