Teen dies after three-car smash in Waikato

A 17-year-old woman seriously injured in a three car collision in Waikato last week has died overnight.

The woman was a passenger in a Suzuki Swift heading west along State Highway 23 near Whatawhata which collided with an oncoming Nissan Bluebird shortly before 10pm on Thursday.

The driver of a Hyundai Sonata following the Suzuki managed to break and avert all but a minor collision with the rear of the Swift.

Police believe the Nissan Bluebird crossed the centre line, smashing head-on with the Suzuki.

The female driver of the Suzuki and a passenger in her car were both taken to Waikato Hospital by ambulance with serious injuries.

The passenger was later flown to hospital in Auckland for surgery.

Police said driver remains in a critical but stable condition in Waikato Hospital, however the 17-year-old female passenger died in Auckland overnight.

The driver of the Nissan suffered serious leg injuries in the crash.

Police said an investigation by the Waikato Serious Crash Unit is continuing this week, with investigators awaiting the results of toxicology tests to determine if alcohol played a part in the crash.