Research

On August 8, 2023, a grassfire outside Lahaina, Hawaii grew into the deadliest natural disaster in Hawaii’s history and one of the top 10 deadliest US wildfires on record since 1871. This tragedy claimed 102 lives, and damaged or destroyed approximately 2,153 structures, with reconstruction costs estimated at $5.5 billion. Elevated wind speeds coupled with the effects of fuel chemistry, density, and continuity—both at the community interface and within the community—resulted in conflagration in Lahaina.

Following the fire, a team from the Insurance Institute for Business & Home Safety (IBHS) collected detailed data on the building materials used across Lahaina and the urban fuel surrounding these buildings to understand the conditions that contributed to the community conflagration. These data explain the relative importance of structure spacing, connective fuels, and building materials in fire spread into and through the built environment and demonstrate the critical need for a system of mitigations to reduce the intensity and likelihood of conflagration.