Learning important risk mitigation lessons through counterfactual analysis of the 2023 Lahaina Wildfires

Counterfactual analysis is the study of what might have happened, if a particular circumstance had been different. This type of analysis is being increasingly applied to the field of disaster risk reduction, to estimate how much the effects of a disaster were prevented or amplified by the presence (or absence) of certain factors. The findings of such analyses can then be used as lessons learned from unrealized alternative events, to help inform policies and plans for a more disaster-resilient future.

This study conducts a counterfactual analysis for the 2023 Lahaina wildfires in Hawaii, which caused over $6 billion in losses and more than 100 fatalities. Using a qualitative approach inspired by previously proposed counterfactual analysis frameworks, we investigate a variety of plausible shifts related to the disaster (e.g., in terms of its geographical location and timing) that could have led to an even worse outcome. We find that the casualty number could have been notably increased if the most significant wildfire occurred at night, near a much larger town in the north of Maui, and/or coincided with a volcanic eruption, for instance.  The results of this investigation are translated into a series of recommendations for strengthening disaster risk reduction measures (e.g., related to improving early warning systems, community-led evacuations, and consolidating public partnerships with transportation companies) that could significantly reduce wildfire-related losses from any future similar events in the region or elsewhere.