The crash happened within minutes of a two-car crash in central Auckland last night.
Six people were injured, two seriously, when the vehicles crashed on Ian McKinnon Dr in Eden Terrace at 10.35pm.
Firefighters were called to the scene to cut one person from a vehicle.
A St John Ambulance spokeswoman said two people were seriously hurt, two had moderate injuries and two had minor injuries.
Three of them remain in Auckland City Hospital this morning.
A 37-year-old woman was undergoing surgery today after sustaining serious injuries.
A hospital spokeswoman said two other victims, a 31-year-old man and a 19-year-old woman, were in stable conditions.
It is believed all three are related.
The other three victims were discharged overnight.
The police serious crash unit is investigating.
Meanwhile, police investigating the Hawke's Bay crash said they would like to speak to the person who picked up the driver and anyone else who may have witnessed the crash.
Anyone with information was asked to call police on 06 873 0500 or Crimestoppers, anonymously, on 0800 555 111.