Mother of three Dominique Cates had a feeling of terror when she saw that her car - her children still inside - was gone.

She had just parked outside surf shop North Beach and ducked inside.

Because of the heavy rain, she decided to leave her children - Keenan, 5, Abel, 2, and 5-month-old Alicia - strapped inside as she would only be a couple of minutes and could see them from inside the shop.

Minutes later a tornado struck, flinging the vehicle about 50m away from where Mrs Cates parked it.

Witnesses said it was lifted at least the height of the shopping centre building, before being thrown down.

Yesterday she was still upset talking about the ordeal, but said she was grateful that all her children were okay.

"It happened very fast, I tell you that much. I'm amazed at how well they're doing. I'm just amazed and just so thankful to God how well they're doing," she said.

"I don't even care about me - but I'm doing fine - I'm just grateful that I have the lives of my children and I'm just thankful to God for that."

The children's uncle, Glen McLeod, was at his workplace nearby when the tornado struck.

After contacting various family members, his brother Isaac - who was in Whangarei at the time - asked him to try to get to his wife, Mrs Cates, and their children, who had been caught up in the havoc.

"He said: 'Dom's been involved in the tornado but the kids are alive. They're scratched and there's blood, but they're alive'," Mr McLeod said.

"I rang her and she was crying and everything so I went up there to help."

Mr McLeod said his sister-in-law was in shock when he arrived.

"She said she had a feeling of terror. She'd turned around to see where the car was and it'd gone. And so the feeling of terror, not knowing where the car - forget the car - but where the kids were.

"It was hideous for her, to be honest. She's been struggling with that.

"But [one of the rescuers] said to me, if she'd been in the car, the way it landed, she would probably have been killed. So yeah, things happen for a reason ... it's been pretty harrowing ... but the kids are all okay."

A woman, shopper Paul Zaloum and Farmers manager Tinus van Liggereberg helped free the children.

Mr Zaloum was shopping in Farmers when the tornado struck.

"We saw a few cars scattered around, and then we saw the white car with the kids and shot off to them."

He said a witness later told him that the car had been lifted to at least the height of guttering on the centre buildings before being thrown 50m, landing on its top.

"I got the kid out of the front seat and [he was] just a real brave little guy and I asked him the normal things, 'how many are in here and are you okay'.

"He was calm. There was blood and stuff around but the kids seemed to be okay. The older one ... he was asking: 'Why did this happen, why did this happen?' ... and he was asking the whole time: 'Why did this happen'?"

Mr Zaloum needed six stitches after he cut his bicep crawling into the vehicle to free Keenan.

He praised the children's mother for making sure all three children were strapped safely into their carseats - a fact Mr Zaloum said saved their lives.

"Carseats are the business. Good on the mum for using good carseats. The car was upside down and they were still strapped in - very little [injury] to them."

All three children had minor injuries and were treated at North Shore Hospital, before being discharged.