The driver - understood to be Pauler - was killed while the other woman in the vehicle was taken to hospital in a critical condition. The passenger remains in hospital with shoulder injuries. A second car was able to take evasive action and ended up in the scrub on the side of the road.
As a result of the collision, the truck driver lost control and crossed the centre line into the northbound lane and a third 4x4 vehicle struck the truck head-on, killing both occupants, a man and woman - understood to be Mr and Mrs Cocker.
The truck driver was taken to hospital in a serious condition with suspected spinal injuries, but has since been discharged.
Autopsies were carried out yesterday. The passenger of the first car and the truck driver had both been spoken to by police.
"We would like to thank the emergency responders for their assistance; Fire and Emergency New Zealand, St John, and the road crews who kept us safe while working on the scene, and the people of Northland for being patient while we cared for and treated the people in this crash and investigated what happened," a police spokeswoman said.
Police were asking anybody who saw the crash, that has not spoken to the police, to contact Whangarei Police on 09 430 4500.
There was plenty of support for the emergency crews who dealt with the tragedy. On the Northland Police Facebook page, local resident Gavin Price had nothing but praise.
"I would like to say a big thank you for the emergency services and the police for the way they handled this terrible accident. We live on Oakleigh Rise and the response times were incredible. Heartfelt condolences for those who have lost loved ones and speedy recovery for those who may be injured."
The three deaths coincide with a campaign run by Northland Road Safety to encourage safer behaviour by drivers on the road. The triple fatality took Northland's road toll to 30.
One of those involved in the campaign, transport projects manager Ian Crayton-Brown, said it was driver behaviour, poor attitude and bad decision-making mainly behind the high road toll.
"Sadly 2017 is proving to be a horror time for totally preventable deaths on Northland roads ... and traditionally some bad months are just ahead of us."
Many of the deaths this year involved people not wearing seatbelts.
"Our current road toll tells us that it is not okay to be complacent, to take risks, and not to respect both yourself and other motorists or road users."
Mr Crayton-Brown said an avoidable error or distraction often led to innocent people being killed or suffering permanent injuries.