He ran across the road at a crossing that was unmanned. It was not a pedestrian crossing, rather part of the road with a pedestrian refuge in the middle. The school patrol had finished supervising the crossing for the morning.
Manuroa Rd resident Charmaine Tuhaka heard the crash and ran out to help.
"I heard a vehicle skidding, and then a big bang. I thought it had hit another car," she told the Herald.
"I went running out and saw the little boy. It was quite horrific."
Ms Tuhaka said the boy was bleeding from his head and she and two others held him still to prevent him moving and further injuring himself.
"He wasn't talking but he was conscious. His eyes were open, he wasn't moving - he wasn't even groaning in pain," she said.
"His sister was there, on the side of the road and she was with a couple of teachers. She was crying. Then her mum came. She didn't say a word she just ran to her son, she was freaking out."
Ms Tuhaka said the boy's mother and sister were in shock.
"The driver that hit him was too. It was horrible," she said.
"I keep thinking about (the 5-year-old), I hope he's alright."
Takanini School principal Stephanie Anich told Stuff.co.nz that the accident was horrible.
Staff were looking after the boy's sister and his mother had travelled to hospital with him in the ambulance.
She said pupils would be reminded about road safety at an assembly today.