Witnesses described hearing the cries of injured children who were lying in the street following the horror crash.
The crash happened near Westlake Girls' High School on Auckland's North Shore shortly before the school day started.
Five people, all students from Girls' High and nearby Westlake Boys' High School, were injured when a car left the road and struck a group on the footpath.
One girl was critically injured and moved from Auckland City Hospital to Starship where she remained in a critical condition last night, an Auckland District Health Board spokeswoman said.
Three other students were stable. One is at Auckland City Hospital and two are in Starship.
A fifth pupil was treated at the scene but did not need to go to hospital.
The driver of the car had been spoken to by police.
He was not injured.
A man the New Zealand Herald understands to be the driver's brother said he had been told by police not to speak to media, but said his brother was doing okay given the circumstances.
"I am praying for them right now," he said of the injured students.
North Shore resident Anna Grygorenko was caught in traffic on Wairau Rd when she drove into the rush-hour nightmare about 8.30am.
As she wound down her window sounds of wailing soared over idling engines.
"There were lots of people and debris on the side of the road.
"I was driving past at the time and it must have just happened as no paramedics or police were on the scene yet.
"I lowered my window to listen for ambulance siren but instead I heard wailing from the victims," she said.
Those mowed down were left spread over many metres. One boy used a backpack as a makeshift pillow while paramedics assessed his injuries.
School pupils were seen comforting each other in the midst of the shocking scene while other adults retrieved school gear.
Cordons remained in place on Wairau Rd on the North Shore yesterday afternoon and the Serious Crash Unit was investigating.
In an email to parents, Westlake Girls' principal Jane Stanley said counselling support was on offer for all students and staff.
"Our thoughts are with the students and families involved in the terrible accident outside our school this morning," she said.
"The emergency services arrived quickly but some of our students have sustained serious injuries and they are all receiving the best possible care in hospital."
"We are providing counselling for all our students and staff at this difficult time.
"Please respect the privacy of the families involved," she said, adding that official media statements would be managed by the school.
"We are very grateful for the support we have received from the emergency services, the local schools and the wider community."
Police remained at the scene yesterday afternoon.
