A Hawke's Bay couple were among the six injured at the horrific gas explosion in the Christchurch suburb of Northwood.
The incident, at 10.14am on Friday, in Marble Court, turned one house to rubble and damaged surrounding properties.
It is understood Havelock North couple, Mike Greaney and Sharon Hart were visiting family in the home that exploded when the incident occurred.
He was transferred to Middlemore Hospital in Auckland on Saturday where there is a serious burns unit. Greaney is in a stable condition, a spokeswoman said, whereas
Hart remains at Christchurch Hospital.
A Canterbury District Health Board spokeswoman confirmed three others are in a stable condition and one is in a critical condition.
It is understood the man in a critical condition, is fighting for his life and on life support.
The couple are members of the Havelock North Club, who posted the news on Facebook just hours after the incident.
In the post, they said their "thoughts and prayers go out to them and their family members for a speedy recovery".
"Thank you to everyone who was involved in helping them get out safely... Neighbours, Fire Service, Ambulance, Police and civilians."
A club spokesperson said they had been in contact with the family.
"They are both going to have a long recovery."
James Looyer, owner/operator of Complete Carpet Installation, had been working a street over when he heard "the biggest bang".
He immediately rushed to the scene. In the process, he filmed what he was seeing.
He carried out one woman, through the rubble and put her on the front lawn. He said due to the impact of the explosion, the occupants were "stone-cold" and couldn't hear what the rescuers were saying.
"When I was speaking to her, she didn't really respond, she didn't really understand what I was saying.
"All she was saying was that her feet were sore, and I just looked down and there was pretty much not much skin left on her feet, I don't know if it was from being grazed along the ground, or however she ended up outside."
Looyer said the people at the scene were aged between 50 and maybe 70.
FENZ area commander Dave Stackhouse said earlier that it was "probably lucky" the house inhabitants were close to the source of explosion when it happened.
"Often with these types of things it's the blast wave that can kill people further away from the actual radius of the initial explosion," he said.
"So I guess we are lucky that we are not looking at multiple fatalities here."
Yesterday afternoon, a police spokeswoman said they were only physically preventing access to 9 Marble Court - the affected property.
She said there will be police and armour guard in the area overnight providing security and assurance to people in the affected area.
The occupants of the other houses are being referred to their insurance companies and the council.
"We can also confirm that five properties including the affected property are uninhabitable."
Enquiries are still ongoing.
Speaking to the Herald on Sunday, Belinda Blanchfield, whose father is in a critical condition, said the incident had left her feeling distraught and worried.
"At this stage, we are very concerned for our families."
Blanchfield said the women are "doing okay" but the families have serious concerns for the men, especially her father who is on life support at Christchurch Hospital.
She thanked everyone for their messages of support and also the "amazing people who helped everyone at the scene".