"Anything's bad up there in the Dome Valley. It's only two or three lanes wide depending on where it is.''
Ambulance communications team leader Glen Taylor said two ambulances and a helicopter were sent to the site.
"One male patient, approximately 30 years of age, has deceased. From the same vehicle, a female patient in her early 40s has got minor injuries and will be transported to North Shore Hospital.
"From the other vehicle, two males approximately 50 years old, have no injuries and won't be taken to hospital.''
He said the males could have been treated for minor cuts or bruises at the scene, but no details were available.
Police are diverting traffic in the area, and a southbound diversion is in place at Whakapirau Rd, Te Te Hana and the northbound diversion is School Rd, Wellsford.
Police said two people died in a single car crash after 2am today on State Highway 2, about 15km south of Hastings today.
A Mitsubishi utility was travelling towards Hastings carrying two people, said Central Communications Inspector Marty Parker.
He said initial reports said two occupants were thrown from the car after the vehicle veered off the road and rolled into a ditch.
The weekend's first fatal crash was on Saturday when a man died in a crash at about 7am in Bayview, Napier.
Two cars collided when one crossed over the centre line on State Highway 2.
A motorcyclist who was in a critical condition after crashing into a fence in Whanganui about 7:30pm on Saturday has also died.
Last year's Labour weekend saw eight fatalities and 125 injured on the nation's roads.
The holiday road toll period started at 4pm on Friday and runs until 6am Tuesday.
