Vagrants were known to be sleeping in an unoccupied Hamilton building which previously housed a strip joint.
There was little holding the Victoria St Calendar Girls in position today after fire ripped through it about 12.15am today.
Up to 50 firefighters from around greater Hamilton fought the fire which saw flames bursting through windows and roof cavities and smoke billowing across town.
The strip parlour is on the city's main street and is nestled next to Biddy Mulligan's Irish Pub and the Victoria Accident and Medical Centre.
The fire took more than an hour to bring under control while firefighters remained at the scene throughout the morning, damping down hotspots.
Waikato fire assistant area commander Daryl Trim said firefighters were this afternoon waiting for a digger to arrive at the scene to remove the roof which had caved in at the back of the property, where the fire started.
They also wanted to double check that there was nobody inside the charred ruin.
He said the building bore the brunt of the blaze, with the adjacent Biddy Mulligan's Irish bar suffering water and minor smoke damage.
The Victoria Accident and Medical Centre was not affected and was back to business today.
Trim said although they knew where the fire started, an investigation would now begin into what caused the blaze.
Andrew Matijasevich owns the three buildings and said they had a new development in mind for the site.
However, when and if that development went ahead would now have to be reassessed sooner rather than later, due to the blaze.
Once the former Irish bar and strip joint had been demolished they would turn it into a temporary car park until they decided what to put there.
He and others had owned the building for about three years and confirmed Calendar Girls had moved out in January.