A suspicious fire which destroyed the upper level of an abandoned Kaipara dairy factory has sparked a reminder for owners to secure derelict buildings.
Ruawai fire services were alerted to the fire at 6.30pm on Tuesday. Crews from Dargaville, Ruawai, Maungaturoto, Whangarei and Paparoa also attended and had the blaze contained by 8.30pm.
Special fire investigator Craig Bain said the fire ruined the upper level of the 100-year-old dairy factory in Ruawai which had been converted to an apartment at one time.
Mr Bain said no one had lived in the apartment for about 10 years. The suspicious fire was being investigated by fire and police.
"At this stage there's no reason why we can see it as accidental because no one was there," he said.