Saturday-Night Booms Rattle New Holstein, Wisconsin

What happened

Early on Saturday 3 October 2026, about 5:30 am, a loud boom woke much of New Holstein, a small city in Calumet County, Wisconsin. Another was heard around 10 pm that night. Mayor Jeff Hebl said he “received a couple of phone calls and a couple of messages on my Facebook page about an explosion that was heard in the city” (FOX 11).

It wasn’t the first. Hebl told NBC 26 this was about the tenth such report “over the past few months.” One homeowner told WBAY the booms seemed to come mostly on Saturdays, between about 1:30 and 5:30 am. “I thought, like one of the trees fell on the roof,” he said of the first one.

The footage

The homeowner’s back-facing security camera, which faces west, recorded a flash of light followed by the bang early on 3 October. His front camera caught nothing. The flash appears from behind a line of trees, and he thinks the source is “farther away than people might assume” (WBAY). WBAY aired the clip in its 5 October report, published at 3:59 pm CDT. NBC 26 showed it to another resident on camera. FOX 11 describes it as a “doorbell camera” clip. The clip’s exact length and timestamp haven’t been published. Its value is that it puts a flash before the sound, which points to a ground-level detonation, not something overhead.

Timeline

• 2 August 2013: The US Forest Service bans exploding targets across its Rocky Mountain Region for a year, citing seven fires since 2012 (Wildfire Today).
• 23 April 2017: A binary exploding target set off at a gender-reveal party starts Arizona’s 47,000-acre Sawmill Fire.
• 2018: The off-duty Border Patrol agent who shot it is sentenced and ordered to pay restitution (US Attorney, District of Arizona).
• About summer to September 2026: Booms are reported in New Holstein, roughly ten times.
• 3 October 2026, about 5:30–5:38 am: The latest boom is caught on a backyard camera. Another follows around 10 pm.
• 3 October 2026, afternoon: The mayor posts on Facebook. Cedar News picks it up. Police then ask residents for doorbell and security footage (NBC 26).
• 5 October 2026: WBAY, FOX 11 and NBC 26 run full reports.
• 6 October 2026: FOX 11 updates its story. An officer has been assigned and the source is still unknown.

What witnesses reported

Residents describe single, house-rattling booms, sometimes heard several times in a night. One neighbor told FOX 11 she had been woken “three different times.” Another resident told NBC 26, “What’s going on? Did someone send off a firecracker? Mortar?”

The mayor told FOX 11 that local theories range “from emptying a dumpster to a ground fault to sewer system you name it, Tannerite.” He added that legitimate construction work would already be known to the city.

What the research found

All three Green Bay stations rely on the same two kinds of evidence: residents’ accounts and one camera clip. The mayor is the only official quoted. He says the explosions are believed to come from the southeast end of town, and he believes “an individual or individuals are behind the booms.” “It’s only a matter of time, they’ll catch them,” he told NBC 26.