Fire and Emergency New Zealand’s Gavin Lack said the fault was in the public bar area of the iconic 139-year-old hotel.
He praised the owner for doing everything right when it came to escaping the burning building.
Lack said having working smoke alarms had saved her life.
"They woke her up as she slept in her bedroom on the first floor . . . she had an alternative escape plan. This was to exit through her bedroom window, onto an escape landing and exterior ladder.
"She would never have got out the main (interior) stairwell, the fire was coming up there," Lack said.
The fire was a reminder to everyone to make sure they have working smoke alarms and alternative escape plans. It also was a warning to be aware about the risk of older buildings, he said.
"You have got an increased risk because of all that dry fuel, and also because of the design and the way those buildings were built," Lack said.
Emergency services received the call from the hotel’s sole occupant as she was evacuating about 1.15am.
Crews from the Sheffield fire station across the road arrived to find the upper level of the building well alight.
They struggled to put out the blaze because of upper roof cavities, and relied on ladders because internal stairs had been damaged.
The fire was extinguished and crews were dampening hot spots by about 7.30am.
Five fire engines, a turntable ladder, a command unit and several tankers were at the fire.
He said it was hard on the community to lose the hotel, which had echoes of the blaze which destroyed the Kirwee Tavern in 2019.
"It will be like Kirwee, the community spirit will drop a little bit because there’s nowhere you can go to meet up with people," Croy said.
Fire investigators at the time determined the Kirwee Tavern fire was caused by an electrical fault due to old wiring.
