In 2017, multiple fires—including the Tubbs Fire—spread rapidly under strong wind conditions, with embers igniting spot fires far ahead of the main flame front. In communities like Coffey Park, closely spaced homes enabled structure-to-structure ignition, leading to widespread losses. 

In 2018, the Camp Fire became the deadliest and most costly wildfire in California history. Driven by extreme wind and fuel conditions, the fire rapidly overtook the town of Paradise, destroying most of its buildings and infrastructure. 

Following these events, IBHS and its member companies conducted detailed post-fire investigations to better understand ignition pathways, building vulnerabilities, and how mitigation and construction practices performed under extreme conditions. 

Key Findings 

• Extreme conditions drive catastrophic losses
  High winds, fuel conditions, and topography can rapidly overwhelm even prepared communities, as seen in Paradise despite prior evacuation planning. 
• Defensible space is critical—but not sufficient alone
  Creating and maintaining defensible space helps reduce exposure to embers, flames, and radiant heat, but no single mitigation strategy guarantees survival. 
• Wildfire risk is a system, not a single factor
  Structure survival depends on a complex interaction of building features, surrounding conditions, and fire behavior—not just individual materials or design choices. 
• Testing validates real-world fire behavior
  IBHS Research Center testing has successfully replicated ignition scenarios observed in post-fire investigations, helping identify effective mitigation strategies. 
• Firefighter intervention plays a role—but cannot be relied on
  While early suppression can prevent losses, many structures can only be protected through proactive mitigation before a wildfire occurs. 

Explore the full report to learn how these findings from all seven fires inform strategies to reduce wildfire risk and improve community resilience.