Research
Every figure on this page is a count we ran ourselves against public records. Where a number came to us second hand and we have not opened the primary source, it is not on this page.
Finding 01 · Florida NFIRS · 2020 to 2025
Every Florida fire report that carries a Fire Module, 2020 through 2025, scored on whether it actually states a cause of ignition. Just under a quarter do not. The rate barely moves between all fires and structure fires alone, which is what makes it a property of the reporting rather than of one kind of call.
The reason flips. Across all fires the largest unresolved group is closed as undetermined: somebody looked and gave up. On structure fires the largest group is still open, filed as under investigation and never returned to. One is a conclusion. The other is a report nobody came back to finish.
Undetermined after investigation U
Still under investigation 5
Not a valid NFIRS code 0
Fire modules examined
172,564
Unresolved cause · all fires
23.34%
Unresolved cause · structure fires
23.26%
Reports carrying an invalid cause code
2,291
Structure fires with no cause stated · including reports filed with no Fire Module at all
56.20%
Source: NFIRS Fire Module records filed by Florida fire departments, January 1, 2020 through December 31, 2025, held in the EMR Inc. research database. Florida only. The percentages above are the share of reports that carry a Fire Module whose cause of ignition field reads 5 (under investigation), U (undetermined after investigation), 0 (not a value the NFIRS specification defines), or blank. The 56.20% figure uses a wider denominator: it additionally counts the 35,416 Florida structure fires filed with no Fire Module at all, where the cause field does not exist to be filled. The Fire Module is required for incident types 100 through 173. These are counts of what was filed. They are not rates, they are not adjusted for population, and they say nothing about any individual department.
Method
Source
NFIRS module records filed by Florida fire departments and obtained as public records. No department supplies us with data privately and no figure here comes from a customer account.
Counted, not modelled
These are counts of what was filed. They are not rates, they are not adjusted for population, and no figure here is imputed, weighted, or projected.
Checked against a load error
A missing field looks identical to a partly loaded database, so every completeness figure is broken out by filing year before it is published. A gap in the data would appear as a year near zero. None does.
Published when it fails
We have tested claims that did not hold and dropped them. Firefighter injury under reporting was one: casualty records agreed with the incident records they belong to, so we do not make that argument.
Florida only. Nothing on this page is a national figure, a rate, or a statement about any individual department.