Two flash-and-boom events, Pueblo, Colorado

Estimated source locations

Shaded circles: estimated source area for each event, generalized to protect the camera locations.

How the distance is worked out

Light arrives effectively instantly; sound travels at about 340 m/s. Distance = delay × speed of sound. Speed of sound is corrected for the air temperature reported at Pueblo Memorial Airport (KPUB) at the time: c = 331.3 × √(1 + T/273.15) m/s. Delay is measured from the flash frame (largest frame-to-frame brightness jump) to the onset of the low-frequency (<200 Hz) audio peak on each camera. The range allows ±0.05 s for camera audio/video sync.

Ruled out: lightning (no satellite-detected flashes within 100 km either night, no thunder at the airport, a single sharp impulse instead of rolling thunder); a meteor (a meteor's sonic boom would arrive minutes later, not seconds). Consistent with: a ground-level point source such as an explosion, large firework, or electrical equipment failure.

Pinpointing the source with a second camera site

One camera site only gives a distance ring. A second site with its own flash-to-boom delay gives a second ring; the source is where they cross. A second, independent camera system about 1.5 km from the first caught both events as well: 17 cameras on Sept 23 and 23 cameras on Sept 24, each with the flash and the boom on the same recording (so clocks do not matter).

• Event 1: The second site saw the flash as a burst on its northern horizon, which picks one of the two ring crossings.
• Event 2: The two rings just touch, so the source lies close to the line between the two sites.

Each shaded circle is 500 m across its radius and its centre is shifted slightly, so it marks the neighborhood-scale area, not an address.

Event 1: Wednesday, September 23, 2026, 8:00:33 PM MDT

Flash

8:00:33 PM MDT (2026-09-24 02:00:33 UTC). Single frame (1/30 s) on every outdoor camera. Rolling-shutter analysis puts the pulse at about 20-50 ms. Warm white on the one color camera (not blue-green).

Boom

One sharp impulse about 0.2 s long, energy mostly 120-500 Hz, small echo 1.7 s later. No rolling thunder.

Delay

6.2 s (camera spread 6.0-6.3 s)

Speed of sound

342.9 m/s at 19.5 C (KPUB temperature)

Source

Located by combining two camera sites about 1.5 km apart; see the map.

Weather

KPUB (Pueblo airport) 7:53 PM: 20 C, wind SE 5 kt, overcast 9,000 ft, light rain 7:55-8:07 PM, no thunder reported.

Lightning

NOAA GOES-19 Geostationary Lightning Mapper: 0 lightning flashes within 100 km (35,606 flashes decoded across the GOES-East view, 7:40-8:20 PM). Nearest: 130 km NNE.

Event 2: Thursday, September 24, 2026, 10:36:29 PM MDT

Flash

10:36:29 PM MDT (2026-09-25 04:36:29 UTC). Single frame (1/30 s) on all 11 outdoor cameras. PTZ North scene brightness jumped from 60 to 127 and straight back.

Boom

Much louder than Event 1: several cameras clipped near full scale. Onset 2.12-2.18 s after the flash on 7 of 8 cameras checked.

Delay

2.15 s (camera spread 2.12-2.18 s)

Speed of sound

341.5 m/s at 17.0 C (KPUB temperature)

Source

Located by combining two camera sites about 1.5 km apart; see the map.

Weather

KPUB 9:53-10:53 PM: 18 to 17 C, wind light and variable, overcast, light rain 10:28-10:37 PM, no thunder reported.

Lightning

NOAA GOES-19 Geostationary Lightning Mapper: 0 lightning flashes within 100 km (50,295 flashes decoded across the GOES-East view, 10:16-10:56 PM).

Public reports

Searched Sept 24-25, 2026: Pueblo Chieftain, KOAA, KRDO, KKTV, FOX21, Pueblo Police and Sheriff posts, Black Hills Energy and Xcel outage notices, Reddit, Fort Carson and Pueblo Chemical Depot notices, and local event calendars (CSU Pueblo football, State Fair, Pueblo Motorsports Park). No report or scheduled event found for either time.

If you heard or recorded either boom, the exact time and your location help narrow the source: two or more recordings with accurate clocks can pinpoint it.