Live: 7.5 magnitude earthquake strikes near Hanmer Springs in South Island - two killed, Kaikoura isolated, Wellington CBD damaged

• For the latest coverage go to our new live blog here.

• Aftershocks have continued to rumble through the night. As of 5am, there have been 278 since 7 o'clock last night and 807 since the 7.5 Kaikoura earthquake, GeoNet says

• Kaikoura locals especially are being warned by Civil Defence to stay prepared for further rattles

• In Wellington, people are being told to use commonsense when in the central city today.

• Some buildings are still being assessed and areas, particularly around Featherston Street, are still cordoned off

• Last night the council said it wasn't clear what public transport would be working in the city today after earlier mass cancellations. People are being urged to car-share where they can

• 600 people stayed at a local marae in Kaikoura. HMNZS Canterbury is on its way from Auckland to also help evacuate 1100 stranded tourists. It is expected to start this job first light tomorrow

• Kaikoura is severely damaged with problems around communications, roads, water and sewage. Last night the Marlborough District Council said there was three days' water left

• Power is intermittent, fuel supplies are limited and Kaikoura's hospital is at capacity

• There have been many landslides, and a number of dams have now formed

• St John kept its National Crisis Coordination Centre operating overnight in Auckland. It says patients are being moved out of Kaikoura as needed

• Yesterday morning's devastating 7.5 quake claimed the lives of at least two people - thousands of others miraculously escaped injury

• A 100-year-old woman and her daughter-in-law were rescued from the rubble of an historic homestead, while her son tragically did not make it

• Richie McCaw involved in rescue mission after deadly South Island quake: "it's a bit scary".

• Residents fled homes in the wake of a tsunami threat - police now investigating 19 cases in which vacant houses were ransacked by burglars

• A massive slip has also closed SH70 to Waiau in north Canterbury

• The cost of the quake is expected to be billions of dollars

• Many schools from North Canterbury to Wellington remained shut yesterday while damage was assessed

• Prime Minister John Key has cancelled his official visit to Argentina to deal with the quake fallout

• Power is out in many areas

• Some main highways remain closed

• Follow us live all day through the blog above and listen to our live coverage on Newstalk ZB

• A 100-year-old woman and her daughter-in-law were rescued from the rubble of an historic homestead, while her son tragically did not make it.

The Elms Homestead in Kaikoura collapsed following the magnitude 7.5 earthquake at 12.02am, and rescuers spent hours searching for the three residents.

A Fire Service spokesman said one of the woman was able to escape the large home themselves, while the other was rescued. The man did not survive.

Well-known locals Pam and Louis Edgar live at the property with Louis' 100-year-old mother, Margaret.

The women have "lost everything," said a relative.

Relatives are desperately trying to get into Kaikoura which has been cut off by large slips blocking the only access roads.

Helicopters are currently being used to evacuate people from the coastal settlement, which still has no power.

EARLIER

At least two people have died and several others have suffered non-fatal heart attacks and minor injuries following the 7.5 magnitude earthquake.

Emergency services have confirmed one death at the Elms Homestead in Kaikoura. Three people live at the historic home. One person was able to escape, one was rescued and third has died. Relatives of the family are having trouble contacting emergency services due to congested phone lines and power cuts.

A second person has died of a heart attack at a property in Mt Lyford and there are reports of several people suffering non-fatal heart attacks in the hours following the main quake.

St John has activated its National Crisis Coordination Centre and has set up local Emergency Operation Centres in the South Island. A spokeswoman said St John staff, resources and emergency equipment have been relocated to higher ground, and resource is being moved to affected areas in order to maintain response capability. Casualty numbers and injury numbers are unknown at this stage.

Speaking from the Beehive's civil defence bunker, Prime Minister John Key said all 16 regions had activated civil defence requirements. Tsunami warnings replace in place for much of the East Coast where ways of up to 2m have already stuck.

If you are in a low lying area on the East Coast of the North, South or Chatham Islands move immediately to higher ground. #eqnz

— National Emergency Management Agency (@NZcivildefence) November 13, 2016

Key said it was important for people to keep following safety advice.

He said New Zealand was in "great shape" to meet any costs from the quakes, but expected there would be significant repairs needed. He also confirm the two deaths.

Acting Civil Defence Minister Gerry Brownlee said the pressing need was to get communications gear in to cut off areas and that would be the first task for the helicopters.

He said there weren't reports of many homes or other buildings brought down.

While there had been reports of items falling from shelves, some cracks in buildings and smashed windows in Wellington the true extent of property damage is being revealed as emergency service workers begin assess infrastructure and homes in the light of day.

Pictures are coming in of large slips and badly damaged roads in the Hurunui District. The small North Canterbury town Waiau, where a bridge has been badly damaged, is shut off.

Kaikoura has also been cut off but reports of bad damage are hard to substantiate due to power cuts, blocked roads and a congested mobile network. Military helicopters would be going there to assess damage and make contact. The Fire Service is also sending a seven-strong Urban Search And Rescue squad from Christchurch by helicopter.

Assessment teams are also being sent to Waiau and Blenheim.

In Wellington the TSB Arena and BNZ Centre have sustained the most damage. There is damage to wharves and the Inter Islander terminal, and the Tory Channel remained closed.

Shipping workers were forced to flee the Kings Wharf freight shipping terminal in Wellington, after cracks began appearing and water spurting from beneath them.

"It was just panic stations," said the man who did not wish to be named.

"Water was coming up from the wharf, we had about five seconds to evacuate."

The man said he and seven of his colleagues all ran out together, and huddled to protect themselves in case glass or debris fell from nearby buildings.

In Marlborough, emergency services are bracing themselves for an influx of calls as people see the extend of the damage.

Rural fire chief Richard McNamara said there was a number of vehicles stuck on State Highway 1, and a helicopter was waiting to survey the road in daylight.

"There will be a few people spending the night in their cars, I would say."

He urged people not to travel unless it was urgent, because there was already congestion.

pic.twitter.com/l3CvxTjo3Q

— Isaac Davison (@isaac_davison) November 13, 2016

"There has been significant tidal movement in Picton and the [Marlborough] Sounds."

McNamara said welfare centres in Rarangi and Waikawa were sheltering about 100 people, including residents of a rest home.

Image 1 of 26: Damage to shopfronts in Picton Photo / Rob Burn Facebook

Buildings have reportedly fallen in Bleheim.

"Fire crews are roving the towns and CBD of Blenheim since the earthquake assisting where they need to and will continue that throughout he day."

Psychologist Nigel Latta has posted advice on social media for coping with the mental impact of the quake, particularly for children.

"Reassure your little people. Keep calm and carry on best message for kids," he posted on Twitter.

"Tell your kids aftershocks are just the earth farting. Have a laugh where you can. Follow news but try and get kids focus off news."

Tsunami therat is for the eastern coast of the south island. anyone near the east coast of the south island should move to high ground #eqnz pic.twitter.com/C3GG01el1l

— National Emergency Management Agency (@NZcivildefence) November 13, 2016

That was a very large shake. We are now looking into the shake and will be with you all shortly with info. #eqnz. https://t.co/2EHSBuUps1

— GeoNet (@geonet) November 13, 2016

That's caused a mess! #earthquake #eqnz #wellington pic.twitter.com/DKg3G9jWzn

— Steve Donaldson (@darthdonaldson) November 13, 2016