This paper discusses an assessment of the total earthquake damage that could be expected to occur in central New Zealand in two large specific events. Damage was defined as a percentage of replacement value of any property in the affected areaf being in fact the properties insured by the New Zealand South British Insurance Group. A definition of an insurance catastrophe event was proposed, and two levels of risk were examined, namely annual risks of 1 in 1000 and 1 in 9000. Significant total damage levels were formed and major uncertainties in all factors in the risk analysis are discussed.