UPDATED 5PM: Katikati Primary School is today mourning the loss of one of its students and praying for the survival of her 12-year-old brother in a critical condition at Auckland's Starship Hospital.

Nine-year-old Jasnoor Kaur died in a head-on crash on State Highway 29 near the summit of the Kaimai Ranges about 4pm yesterday.

The nine-year-old girl killed in a crash on the Kaimai Ranges overnight was a pupil at Katikati Primary School.

Her two brothers, aged five and 12, were in the car with their sister and are today fighting for their lives.

Waikato District Health Board communications manager Mary Anne Gill says the 12-year-old boy has been transferred from Waikato Hospital to Starship this afternoon in critical condition.

The third sibling, a five-year-old boy, is in a critical but stable condition in Waikato Hospital's Intensive Care Unit.

All three children were travelling in a blue Subaru legacy, along with two women, aged 20 and 34, also from Katikati.

The vehicle collided head-on with a Nissan van that crossed the centreline as it came around a left-hand bend heading from Tauranga towards Hamilton, say police.

Jasnoor died at the scene, while the rest of her family was taken by ambulance to Waikato Hospital.

She is being described as a 'popular, bright and happy girl” who will be sadly missed by her friends, classmates and school staff at Katikati Primary School.

Katikati Primary School Board of Trustees chairman David Freeman says the Jasnoor will be 'fondly remembered, by all who knew her”.

David says her younger brother is a new entrant at the primary school.

'He is in hospital, but he appears he will pull through. She had an older sibling in the vehicle also, who is in a critical condition and is not looking too good.

"We are all thinking of and praying for her family and friends and offer our support and love to them."

Jasnoor's death, and the condition of her brothers, will be discussed at a full school assembly this afternoon, says David.

'The school all knows who she is. We are very conscious, because we have young children at the school, of the impact on them.

'We have councillors being made available and some more stuff will happen early next week as well.”

A 56-year-old Mount Maunganui man, who was the driver and sole occupant of the Nissan, was taken to Tauranga Hospital where he was this morning listed as in a serious but stable condition.

A 79-year-old woman in a Honda Civic that was travelling behind the Subaru Legacy towards Tauranga when it too crashed is today in Tauranga Hospital in a 'comfortable” condition, a Tauranga Hospital spokesperson confirmed today. Another person in the Honda – a 57-year-old woman – received minor injuries but was not taken to hospital.

Western Bay of Plenty road policing manager Senior Sergeant Ian Campion wishes to thank members of the public who stopped to help at the scene.

"Police enquiries are continuing and Crash Investigators will complete a scene survey and analysis."

Read more about the crash here.