Police in Hastings have started an investigation into a fire which destroyed parts of an old hospital building in Waipukurau.
At one stage, more than 60 firefighters were fighting the blaze, which started at about 1.30am on Monday in the second floor of a lift well.
The Fire Service says the fact there were two seats to the fire means it was deliberately lit.
Three fire crews stayed overnight to contain any hotspots in one of the former wards, and another crew with a hydraulic ladder is still at the scene.
A demolition crew is also working there.
Police are keen to hear from anybody who may have seen people acting suspiciously in the area.