For the second time in four months, Baraboo residents have reported unexplained flashes of light accompanied by loud booms.
The Baraboo Police Department received reports before 3 a.m. Sunday of flashes and thunderous bangs from locations on Tenth Street, Birch Street, Park Street and numerous other areas.
Officers who heard the bangs themselves believed they came from somewhere south of the city, according to a police report. But they were unable to determine who or what caused them.
Eric Kaun of Reedsburg was walking near Pierce Park when the first incident occurred. He said he witnessed a flash in the sky. About three seconds later, he heard what sounded like the crack of a gun, but much louder.
"It wasn't a firework," Kaun said. "It was more of a strobe-light effect that lit up the entire night sky. And there was no residual gunpowder flare falling from the sky."
About 45 minutes later, he said, he saw the same thing from the window of a friend's house. Some reported a third boom at some point later in the morning, but Kaun said he did not witness that one.
"Presently, we have no idea what the source is," said Baraboo Police Lt. Rob Sinden, adding that police also do not have information that could definitively link the Sunday booms to the ones that citizens reported in April.
The two April booms also occurred in the early morning hours of a Sunday, and were separated by about 45 minutes.
Just like the booms reported this week, witnesses said they saw flashes just seconds before thunderous bangs shook the area.
The April incident happened just weeks after another small Wisconsin city west of Green Bay experienced unexplained booms of its own.
Clintonville officials eventually were able to confirm - with the help of the United States Geological Survey - that at least one of the booms was an earthquake that measured 1.5 on the Richter scale.
That city now sells T-shirts that say "I Survived the 1.5" and plans to use the profits for beautification projects that will be determined by the mayor at a later date.
Officials have said the Baraboo booms likely are not earthquakes, because they have been accompanied with flashes in the sky.
A lead meteorologist with the National Weather Service in Dodge City, Kan., initially speculated the April 1 booms were "bolts from the blue" - which occur when a storm produces lightning strikes in a clear-sky area up to 40 miles outside the system.
During the April booms, there was a thunderstorm system to the city's southwest headed toward Dodgeville. But there were no nearby storm systems when the most recent bangs occurred.
"There was nothing Sunday morning," said Rudy Schaar, a meteorologist with the National Weather Service's Sullivan office. "There was some stuff Saturday, but that was south of Wisconsin. It moved off Saturday night."