The fact there was no power to the place and it was “supposedly secure” led him to that conclusion, he said.
He went to the fire around 1.30am Sunday and returned during daylight to carry out his investigation.
There were reportedly squatters living near the building though it is not yet known who was responsible for the incident. There were no reports of injuries.
Bain said no matter the circumstances, people have “no right” to deliberately set a fire.
A resident whose home overlooks Beach Rd said they saw a “glow” in the sky just after midnight but thought it was firecrackers.
They had observed graffiti on the building regularly and said it usually looked “very unkept”.
They were shocked to hear it had burned down overnight.
Other Onerahi locals flocked to the site on Sunday morning having heard about the incident through Facebook community pages and word-of-mouth.
The ground surrounding the building had some damage from the fire. Photo / Brodie Stone
The smell of ash lingered in the air even hours after the fire had been extinguished. Graffiti was still visible on one wall of the building which sat burned and unsteady.
One side of the building remained upright despite the blaze. Photo / Brodie Stone
She noted “riff-raff” used to come around often, so the building was getting “a little bit derelict”.
“It’s been unused for so long. I just hope they can build something nice out of it,” she said.
The land on which the building sat overlooks Limestone Island on Whangārei Harbour, and Whangārei Heads, a spot which she described as “beautiful”.
One couple who drove up to see the devastation said they weren’t surprised by the event.
A police cordon was in place earlier on Sunday but removed a few hours later. Photo / Brodie Stone
“We walk the dog past here most days and it’s a pity to have seen it just sitting there falling apart.”
“There were a lot of people around here a lot of the time so I guess it’s not surprising that someone’s taken it too far,” they said.
Broken windows and rubbish dumped nearby were not an uncommon sight, residents also noted.
Brodie Stone is the education and general news reporter at the Advocate. Brodie has spent most of her life in Whangārei and is passionate about delving into issues that matter to Northlanders and beyond.