A fire ripped through a hostel in New Zealand's capital overnight, killing at least six people and forcing others to flee the four-story building in their pajamas in what a fire chief on Tuesday called his "worst nightmare."

Fifty-two people in the Loafers Lodge hostel in Wellington had been accounted for, but firefighters were still looking for others, said Wellington Fire and Emergency District Manager Nick Pyatt. He said they were called to the hostel at about 12:30 a.m.

Authorities told local media that 11 people were still unaccounted for and that the building had no water sprinklers. 

Prime Minister Chris Hipkins told the AM morning news program that he understood that six people were confirmed dead and the number of fatalities would likely rise. Police said they did not have an exact count of the number of dead, although they believe the total number of fatalities was less than 10.

"This morning I went and thanked the Fire and Emergency crews attending the tragic event at Loafers Lodge in Wellington. Alongside our other first responders they have done an amazing job in horrific circumstances," Hipkins wrote on Instagram. 

Hipkins said the building was not currently safe for police to enter and it could take authorities some time to confirm the number of dead.

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"It is an absolute tragedy. It is a horrific situation," the prime minister told reporters. "In the fullness of time, of course, there will be a number of investigations about what has happened and why it happened. But for now, the focus clearly has to be on dealing with the situation."

Responding to comments from emergency officials that the building had no fire sprinklers, Hipkins said it was not currently a requirement of New Zealand's building code for older buildings to be retrofitted with sprinkler systems.

Loafers Lodge resident Tala Sili told news outlet Stuff that he'd been surrounded by thick smoke and could feel the heat from the fire although couldn't see the flames.

"It smelled like poison," he said.

Sili said he jumped from a window to escape and sprained an ankle.

Other residents told reporters that fire alarms would regularly sound in the building, possibly from people smoking or overly sensitive smoke monitors, so many had initially thought it was another false alarm.

Pyatt, the fire chief, said his thoughts were with the families of those who had perished and with the crews who had rescued those they could and tried to rescue those they couldn't.

"This is our worst nightmare," Pyatt said. "It doesn't get worse than this."

Police said the cause of the fire was not immediately known.

Wellington City Council spokesman Richard MacLean said city and government officials were helping about 50 people who escaped the fire and were at an emergency center the council set up at a local running track that had showers and other facilities.

He said a number of elderly people had escaped the building with only the pajamas they were wearing.

"A lot are clearly shaken and bewildered about what happened," he said.

The hostel provided a combination of short-term and long-term rentals, MacLean said. He didn't have all the details, he said, but he believed it was used by various government agencies to provide clients with needed accommodation.

Health authorities said two people who were in the building were being treated at hospitals and both were in a stable condition. Three others had been treated and discharged, while a sixth patient had chosen to leave before getting treatment.

Loafers Lodge advertises itself as an affordable place for people to stay while they are in the capital, whether on business or needing to visit the nearby Wellington Hospital. It has 92 rooms and promotes them as being available long term.

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• New Zealand
• Fire