ZIP 37721 recorded 35 fire and hazmat incidents in 2025, 190 across 2021–2025. Primary county: Knox County, TN. FEMA NRI rates wildfire risk here as High.
190 incidents from 2021 through 2025 inside this ZIP.
| Year | Incidents | |
|---|---|---|
| 2021 | 33 | |
| 2022 | 24 | |
| 2023 | 56 | |
| 2024 | 42 | |
| 2025 | 35 |
Nov peaks. Aug dips. Aggregated across all 5 years inside this ZIP.
Top 5 NFIRS incident types for ZIP 37721 across 2021–2025.
| # | Incident type | Count | Share | |
|---|---|---|---|---|
| 1 | Building fires | 38 | 20.0% | |
| 2 | Brush, or brush and grass mixture fire | 24 | 12.6% | |
| 3 | Unauthorized burning | 24 | 12.6% | |
| 4 | Authorized controlled burning | 17 | 8.9% | |
| 5 | Passenger vehicle fire | 9 | 4.7% |
For the 5 building fires reported here in 2025, here's how investigators classified ignition cause.
NFIRS Area of Origin for ZIP 37721 fires across 2021–2025.
| # | Area of origin | Count | Share | |
|---|---|---|---|---|
| 1 | Undetermined | 13 | 18.6% | |
| 2 | Open area - outside; included are farmland, field | 10 | 14.3% | |
| 3 | Engine area, running gear, wheel area | 7 | 10.0% | |
| 4 | Wildland, woods | 6 | 8.6% | |
| 5 | Common room, den, family room, living room, lounge | 3 | 4.3% | |
| 6 | Substructure area or space, crawl space | 3 | 4.3% | |
| 7 | Outside area, other | 3 | 4.3% | |
| 8 | Storage: supplies or tools; dead storage | 2 | 2.9% | |
| 9 | All other areas | 23 | 32.9% |
NFIRS HEAT_SOURC code — the physical thing that started the fire.
| # | Heat source | Count | Share | |
|---|---|---|---|---|
| 1 | Undetermined | 39 | 55.7% | |
| 2 | Hot ember or ash | 6 | 8.6% | |
| 3 | Arcing | 5 | 7.1% | |
| 4 | Cigarette lighter | 3 | 4.3% | |
| 5 | Radiated, conducted heat from operating equipment | 2 | 2.9% | |
| 6 | Match | 2 | 2.9% | |
| 7 | Radiated heat from another fire | 2 | 2.9% | |
| 8 | Flying brand, ember, spark | 2 | 2.9% | |
| 9 | All other sources | 9 | 12.9% |
Largest single-incident losses in ZIP 37721 across 2021–2025. These 8 fires alone account for 871% of the ZIP's 2025 reported total.
| # | Property loss | Type | Year | Severity |
|---|---|---|---|---|
| 1 | $258,000 | Building fires | 2024 | Major |
| 2 | $92,400 | Building fires | 2023 | Significant |
| 3 | $90,000 | Building fires | 2023 | Significant |
| 4 | $88,000 | Building fires | 2024 | Significant |
| 5 | $72,868 | Building fires | 2023 | Significant |
| 6 | $60,000 | Camper or recreational vehicle (RV) fire | 2025 | Significant |
| 7 | $55,080 | Building fires | 2023 | Significant |
| 8 | $47,780 | Building fires | 2023 | Significant |
Some ZIPs span multiple cities. Ranked by 5-yr NFIRS incidents inside ZIP 37721.
Some ZIPs span multiple counties. The primary above is the largest by population weight; secondary counties are below.
| County | State | Weight | |
|---|---|---|---|
| Union County | TN | 1.00 | FIPS 47173 |
The figures above are historical. For today's air quality, fire-weather warnings, and active fires, go to the official sources.
NFIRS reports each fire incident with a 5-digit address ZIP. We aggregate those rows directly to produce ZIP-level totals — 190 incidents in this ZIP across 2021–2025. Building-fire breakdowns (Area of Origin, Heat Source, ignition cause) only count fires investigators classified beyond the basic incident report. Because NFIRS reporting is voluntary, totals are a strong indicator rather than a complete census.