Fire Cause Guide
Unknown / Under Investigation
The cause has not yet been determined and may be under active investigation.
Why are some fires "Unknown"?
Fire cause determination is a complex forensic process. A fire's cause may be listed as Unknown for several reasons:
- Active Investigation: Fire investigators are still examining the origin area, interviewing witnesses, and analyzing evidence.
- Destroyed Evidence: Intense fire behavior may have consumed the point of origin, making cause determination impossible.
- Remote Location: Fires in extremely remote areas may not receive investigation resources due to access limitations.
- Multiple Possible Causes: Evidence may point to several possible causes without conclusive determination.
The Investigation Process
🔍 Origin Determination
Investigators work inward from the fire perimeter, reading burn patterns and char indicators to locate the precise point of origin.
🧪 Forensic Analysis
Soil samples, debris, and accelerant residues are collected and analyzed. Satellite imagery and lightning strike data are cross-referenced.
📋 Classification
Once investigation is complete, the fire is reclassified as lightning-caused, human-caused (with subcategory), or remains undetermined if evidence is inconclusive.
What This Means for the Public
"Unknown" does not mean "unreportable" — smoke reports, weather observations, and eyewitness accounts all help investigators narrow the cause.
If you witness a fire start — even one already burning — your report through the Report Fire page contributes to situational awareness. Investigators cross-reference public reports with lightning data, satellite thermal anomalies, and ground-truth evidence to classify each fire. See Fire Records for historical cause breakdowns by year and region.