The man said two women picked him up and put him on the grass berm. They were trying to get him to speak but the boy was unconscious. He said one of the women tried to open his mouth but couldn't.
"The lady was trying to get him to respond, but he was quite unconscious, he wasn't moving.
"When something hits a body, which is soft tissue, flesh, you don't expect to hear such a bang.
"The car must have tossed him through the air.
"It's pretty sad."
The neighbour said he didn't notice any obvious injuries and there was no blood but the boy was wearing a shirt.
He said the driver of the car that hit the boy looked to be a woman in her late 20s and was probably in shock from what happened.
A woman who lives nearby the accident said they'd had ongoing road works on Te Atatu Rd for at least a year. As a result their road had seen increased traffic from drivers trying to take short cuts around the congestion.
"It [the accident] is a horrible thing to have happened and the family just need to recover from it."
The $30 million Te Atatu corridor improvement project is currently underway on Te Atatu Rd, which Jaemont Ave runs off. The project started on September 14 last year and is expected to be completed in the first half of 2017.
At the scene yesterday, Inspector Shawn Rutene said the boy ran across the road, where he had been hit.
"What's occurred here is that a young child, age of 3, has run across the road in front of a moving vehicle and as a result of that, child is in Starship Hospital with serious injuries.
"This is not a driveway incident. There's a lot of inquiries to be made, but at this point in time, the families are being supported by their own and by police.
"The driver of the vehicle that has hit the child is being supported.
"The message is: We're heading into the school holidays. Users of the road, parents and caregivers need to be vigilant in and around these areas - even these quiet streets."
The Waitemata Serious Crash Unit attended the incident.
It is understood the child had been with a caregiver who was visiting a property on the street when he ran onto the road.
