The Pigeon Valley bush fire that rampaged across the Tasman region in February was one of the biggest blazes in New Zealand's modern history. It covered 2300 hectares and saw thousands flee. While fire officials undergo an operational review, hundreds of internal alerts and 111 calls have been released to the Herald. Kurt Bayer reports on the anatomy of a disaster.

The grass was so dry it was a pale shade of yellow. So when Joel Scott drove past and saw leaping flames, he knew it was bad. Really bad.

He dumped his ute in the middle of the road and ran towards the fire. He fumbled for his phone and punched 111.

"We're going to need a chopper real fast," he tells the call operator at 2.14pm on February 5 this year.

He says the location, up Pigeon Valley Rd, about 30km south of Nelson.

"Okay, all right. And what exactly is on fire?" the call taker asks.

"The bush and it's spreading real fast."

Scott took the first photo of the fire. Within minutes, it had gone from "the size of a barbecue fire" to galloping up and over a hillside, into a vast forestry block.

As he talked to the contract tractor driver who's understood to have inadvertently sparked the blaze when disc-ploughing a farmer's field, other emergency calls flooded in.

"Look I'm just down the valley a bit further and it looks like there's a scrub fire heading up, heading up the hill. Yeah it's heading up the f****** forestry mate," says a second 111 caller at 2.19pm.

"You might want to get some choppers and everything, she's f****** just flying up the hillside."

Joel Scott was driving through Pigeon Valley on February 5 this year when he noticed flames. He was the first person to alert emergency services. Photo / Supplied

Then Scott dials 111 again, hammering home the urgency required.

"Ah, it is humming, it is absolutely humming," a transcript of his call states.

"It's gone from when I was here it looked like a barbecue smoke and now it's four, five acres are already engulfed in the forest.

"You're going to need choppers, not fire engines."

Wakefield Volunteer Fire Brigade, at the very bottom of Pigeon Valley Rd, were alerted to a vegetation fire at 2.16pm, according to the Fire and Emergency NZ (Fenz) SMS incident report released to the Herald under the Official Information Act legislation. Brightwater units were roused about the same time.

The first Wakefield fire truck got there at 2.26pm, followed by a Brightwater appliance at 2.34pm.

And the emergency calls kept coming – 13 in 22 minutes. There would be 27 calls in total.

Fire and Emergency NZ's internal message log first records details of a bush fire at 2.15pm. One minute later, it notifies of "a large bush fire – spreadin [sic] due to winds".

By 2.20pm, a fire lookout operator stationed on the Barnicoat Range above nearby Richmond has directed the first helicopter to respond.

Five minutes later, two more choppers are diverted from a fire in the Waihopai Valley in the Marlborough region.

The first helicopter arrived on the scene at 2.40pm, Fenz told the Herald this week. Two more arrived at 2.45pm.

But even though it took just 26 minutes to scramble a chopper and for it to arrive, the blaze was already out of control.

"I suggest they get every helicopter they can get their hands on, now," says a frantic Brightwater farmer calling 111 at 2.48pm.

"They need helicopters, not land-based. They're going to need helicopters … It's getting bigger by the second … It's blocking out the sun now. But they need to – have they got helicopters out there?"

A helicopter using a monsoon bucket fighting the Tasman bush fires near Wakefield, Nelson. Photo / Leon Menzies

Within 50 minutes of the first station alert coming through, 11 fire appliances from across the region had arrived on the scene.

Just over an hour later, a central fire command point was set up.

Giant grey and black clouds billowed high over otherwise blue Tasman skies, eclipsing the sun, daytime gloom. Ash rained down on to washing lines. Cars pulled over to the side of the road, people craning for a better look.

The SMS incident report shows fire bosses seeking weather forecasts as concerns mount over the blustery, hot south-west winds fanning the inferno. The temperature was 26C and winds gusting to 65km/h.

By 4.42pm on that first day, discussions were already being held on whether they needed to establish an Emergency Operations Centre (EOC).

Flames were reported to be leaping to 30m in the air as the 700m-wide fire front had travelled approximately 2km in just two and a half hours.

It was travelling north-west towards the populated Eves Valley by late afternoon.

By 5.30pm, the fire service was getting calls from concerned tourists over whether they needed to evacuate their coastal camping grounds some 15-20km away.

Homeowners were also ringing in asking whether they needed to gather up their things and escape.

An evacuation centre had been set up at St John's Anglican Church in Wakefield.

Locals viewing the massive smoke cloud from the Tasman bush fire near Pigeon Valley. Photo / Mark Mitchell

By 6.33pm, the fire was "uncontained", with five helicopters attacking it from the air.

Residents in Eves Valley and Teapot Valley were by now being evacuated.

Ground crews pulled out of Eves Valley shortly after 8pm "and leaving it to the helicopters as it is too dangerous". But by about then it was getting too dark for the helicopters to safely operate.

And as night fell, it was descending on Redwood Valley, sending fire appliances to retreat to the police cordons.

A three-bedroom house in the upmarket Redwood Valley with panoramic north-facing views down to the Nelson bays was burned to the ground.

The owner of the engulfed home feared his multimillion-dollar Spanish-style mansion just metres away had also gone up in flames.

That night, he stood at the bottom of his hill watching flames "very quickly come over the ridge and move down" towards his property.

"It was a line of fire, just swiping down …" said the homeowner who only wanted to be known by his first name, Michael.

Soon afterwards, there was an "explosion" which he assumed was his cottage "going up in flames".

Around midnight, he got an alert from his security alarm company saying the property was on fire.

"It was absolutely devastating," Michael said.

A three-bedroom house in Redwood Valley was destroyed in the February 2019 blaze. Photo / Supplied

He was very thankful firefighters managed to save his main house, with flames getting to within metres of it, even charring wooden beams protruding from under the eaves, and melting plastic downpipes.

"I just don't know how to express my gratitude to these guys," Michael said.

"I say thank you to them two times a day.

"Those brave and fearless guys saved not only my property but those around me.

"I have no doubt that they went well above and beyond the call of duty to save homes."

By the next morning, Pigeon Valley was deemed "safe", but residents still weren't allowed home.

Some landowners were escorted back to grab pets and transport livestock.

One farmer at Redwood Valley lost more than 60 sheep.

"It was pretty horrible, to say the least," said agricultural contractor, TB tester and part-time farmer Steve German.

That afternoon the Redwood Valley fire was contained around the houses.

Sixteen aircraft were available for the aerial assault. Six more were available by day two, along with two fixed-wing aircraft which were used to drop fire-retardant.

Over the following days, a total of 61 units from across the country were scrambled to join the fight.

It would be the biggest ever aerial firefighting operation in New Zealand's history.

The blaze spread across 2316 hectares, spanning 36.4km – a greater area than the devastating 2017 Port Hills fires in Christchurch.

After 22 days, Civil Defence lifted the state of emergency.

Fenz says it is undertaking an independent operational review of its response to the Tasman fires.

"We will consider the findings once it has been completed," says national manager response capability Paul Turner.

However, the "indicated cause" of the fire is "operating equipment and machinery", according to the SMS incident report. The certainty of cause is "high", it says, which matches the initial eyewitness reports, and comments by Fire and Emergency NZ (Fenz) incident controller John Sutton who confirmed two days into the blaze that it was almost certain the fire was the result of agricultural machinery.

PIGEON VALLEY FIRE – A TIMELINE

• Sometime after 2pm on February 5, 2019, a contractor disc-ploughing a Pigeon Valley farmer's field inadvertently sparks a fire.
• 2.14pm: Passerby phones 111 to alert them about a scrub fire: "We're going to need a chopper real fast."
• 2.16pm: Wakefield Volunteer Fire Brigade alerted to vegetation fire
• 2.19pm: A second 111 call: "You might want to get some choppers ... she's f****** just flying up the hillside."
• 2.20pm: A fire lookout operator calls for a helicopter to help.
• 2.26pm: The first fire appliance arrives on the scene.
• 2.40pm: The first helicopter arrives to attack the blaze from the air.