Police have confirmed a newborn baby was among the six victims of a head-on crash on SH3 north of Waverley this morning.
The crash happened near the racing club in Waverley about 11.11am.
Six people died at the scene - four elderly people in a car heading north, and a male driver and the baby in a vehicle heading south.
A woman who was the front-seat passenger in the southbound car has been flown to Wellington Hospital with critical injuries, while an 8-year-old girl who was also in that car has been taken to Waikato Hospital.
Authorities were still attempting to notify the next of kin.
Waverly fire and emergency chief Alan Hickford said it was known who the deceased were and where they came from, but police had been unable to contact all their family members.
He said the identities would only be released once that was complete.
Road Policing Manager Inspector David White spoke to media at 3.30pm, and said the Serious Crash Unit was investigating.
He said it was clear the vehicles had impacted head on.
Watch the police press conference:
He said the weather was clear and the road was dry at the time of the crash, which happened on a slight bend in the road.
"This is a devastating crash and the tragedy will affect a large number of people in our community.
"Our sympathies and condolences go out to the family, friends and loved ones of those involved."
The road reopened about 6pm.
A line of 50 heavy trucks were left stranded either side of the accident scene this afternoon.
Hawera truck driver Robert Clegg said he drove on the stretch of road every day and it was not particularly dangerous.
Mr Clegg said he drove through the corner where the accident occurred about 9am this morning, and it was not slippery or affected by ice.
Carol Ball, a witness to the crash, said she and her partner heard a loud 'bang'.
"It was earlier this morning that we just heard a 'bang' and I looked over and saw a lot of dust. I thought it was a truck that dropped a bag of cement off, it was just like a whole lot of dust going up and then my partner said there's been an accident.
"There were about three fire brigades that came and then an ambulance and then three helicopters came as well.
"We didn't like to go down there because there was a lot of people there."
Another witness, Brian Martin, said it was a dangerous corner to drive.
"That is a dangerous corner that corner there, a lot of people don't really slow down and if you're coming from the other way you can get across the road and if a vehicle was passing the other vehicle on the left hand side and the other one was coming around the corner they could quite easily have a head on accident there."
Waverley Racing Club secretary Justine Alexander said there was a blind rise on the road, before a big long straight, that acted as a blind spot.
Ms Alexander did not know if the people hurt and killed in the crash were locals, or driving through.
Fire and Emergency had three vehicles on the scene and helped release passengers trapped in the crash.
Police this morning warned motorists about ice on the road, with four car crashes after 5am.
Just after 5am a car rolled on Mawhitiwhiti Road in Okaiawa, the driver was taken to hospital to be examined.
At 6.30am another vehicle crashed into a fence and rolled onto its side at Broadway in Stratford.
Police also received a report that two cars had crashed off South Road, at Tokaora, after hitting ice. One ended up in a ditch, the other in a paddock.