Police have named the three men killed in yesterday's tornado as Tom Stowers, 42, of Massey, Keith Langford, 60 of Tuakau and Brendon Johnson, 22, of Massey.
They died when they were crushed by a falling concrete slab on the Hobsonville High School construction site, while they sheltered in a truck.
The fatal storm also left dozens injured and hundreds displaced when it slammed into the Hobsonville-Whenuapai area of West Auckland yesterday afternoon.
Civil Defence says the damage inflicted would cost $11 million to repair.
At least 150 homes were destroyed, with a total of 230 people left homeless, with some accommodated the Whenuapai Air Force base.
Two recovery centres would open this morning with agency staff onsite to help those displaced.
Heavy rain was predicted for the area today, with possible hail and showers. Wind gusts of up to 100 kmh were expected. The most intense rainfall would be this evening, forecasters said.
Prime Minister John Key would visit the site at 11am today.
Waitemata Police District Commander Superintendent Bill Searle said civil defence were working as quickly as possible to establish which houses in the affected area of Hobsonville were safe for their owners to return.
"In the meantime I ask everyone to be patient, " he said.
GUSTS MOST DAMAGING
While the tornado in Auckland packed winds of more than 200kmh, some of the most damaging winds were the "striaght gusts" which came immediately before and after the mini twister, MetService said.
Meteorologist Dan Corbett said straight-line gusts of up to 110km were what caused considerable damage out at Whenuapai.
"The mini tornado obviously does some serious damage but they also have the potential to kick out some serious winds as they release."
He said a "cold upper pool" was hovering over parts of the North Island today giving moderate risk of thunderstorms particularly in the North Island, particularly from Waikato down.
"We can't rule out the risk of tornadoes in those areas," he said.
Wellington was also at risk of thunderstorms in the afternoon, although no tornado risk was presumed for the capital - just heavy hail.
The tornado inflicted at least $11 million of damage, civil defence says.
A North Shore Hospital spokeswoman said only one patient had been kept in overnight. The woman had suffered a fractured pelvis during the tornado.
She was in a comfortable condition.
Power supply company Vector says around 1300 homes lost their power in the storm, and a lightning strike in Piha, and by this morning 635 homes, mainly in the storm area, were still without electricity.
The company says they will not be restored until authorities check that the damaged homes remain safe.
LINE OF THUNDERSTORMS
Auckland and a swathe of the North Island which included Rotorua and Gisborne were hit yesterday afternoon by an intense line of thunderstorms and heavy rains.
Another tornado touched down near Rotorua without injuries.
The worst damage was inflicted near the Whenuapai air force base and on nearby Hobsonville, a former air force base now being transformed into a large housing estate.
Most of the damage was done to Defence Force housing.
Defence Force staff and civilians accommodated at Whenuapai Air Force base showed a variety of emotions, Group Captain Kevin McEvoy told Radio New Zealand.
"Obviously they are happy to at least be safe, but some of them have obviously lost their houses and belongings," he said.
The response to the tornado was a major coordinated activity, he said.
"New Zealand police have got the lead, but we've been supporting them throughout the night; St John, Civil Defence, Auckland City Council, Red Cross, and the list goes on."
DISASTER RESPONSE 'OUTSTANDING'
Auckland mayor Len Brown said the response to the disaster by authorities was outstanding.
"We have learnt a lot from Christchurch," he told Radio New Zealand.
The response had huge pace and momentum.
"The community would have felt absolutely embraced and supported," Brown said.
He appealed for people to stay away from the area today unless they could help, and he asked that the families of the dead be respected.
"I am very focussed on the families, there have been three bereavements and three men did not come home last night."
Brown said the residents had been hugely traumatised.
The storm had gone through the area several times: "It had gone around it like the tub of the washing machine."
Brown said he would spend the day talking to residents in the area.
VICTIM 'LIFE OF THE CONSTRUCTION SITE'
The fatalities happened at the site where a new school is being built.
Contractors were working on the new high school when 15-metre high concrete tilt-slab walls were picked up by the storm and slammed into sheltering workers.
"There was about two or three of them that tipped over and a couple landed on the truck and one landed half on the ground and half on the truck,'' plumber Sam Nuthall said.
"That was the one that landed on top of the two guys.''
The three men killed were in the truck or beside it.
One of the men killed had been ''the life of the construction site'' he said.
He said he had a bit of a laugh with the man, he named as Tom [Stowers].
Nuthall said he'd been nagging Tom to move a support brace so that he could move his digger and they ''had a bit of a chuckle about that''.
Rescuers needed a large crane to remove the concrete and it wasn't until early last night that the bodies were recovered.
The tornado inflicted damage along around a kilometre of Wallingford Way - named after Sidney Wallingford, one of the founding pilots of the air force - where 220 homes were declared uninhabitable.
WHOLE ROOF BLEW OFF
Residents were recounting their lucky escapes.
Alex Butson was outside getting the washing in as it started to rain when suddenly the storm hit and he ran to his girlfriend Melanie Kassian as windows started breaking.
''I ran down and threw her under the stairs. That's when the second window and top window blew out.''
As they huddled under the stairs, the whole roof blew off.
Rochelle Good's home had its carport crushed by a fallen tree and the power is out.
She could have stayed on, but admitted she was too shaken.
She and her three children left to stay with her parents elsewhere in Auckland.
Homeowner Debbie Booty took shelter in the bathroom but one by one the windows blew in, leaving broken glass coating the floors of her home.
She took shelter in a hallway cupboard. When she emerged into her hallway she looked up at where her ceiling used to be and saw the sky.
Walls were broken and almost every window smashed.
"I'm just shaking and in shock,'' she said.
She joined about 250 other people driven from their homes who were sheltering at near-by Whenuapai Air Force Base.
''It's just so close to Christmas. We're safe though, everything else is just things."
Hawkins Construction, who hold the main contract on the school site, said there were ''fatalities and injuries suffered by a number of subcontractors''.
Executive general manager Dan Ashby said the company's immediate focus was on supporting the affected workers' families, and its staff and subcontractors on site.
George Grant Engineering did not want to comment.
A Department of Labour spokeswoman said the department were not involved as it appeared to be an ''act of God''.
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