Just before 1 o'clock Wednesday afternoon, people in Monroe County and beyond heard a disturbingly loud "boom." It was reported in neighboring counties as well, and remains a mystery.

Whatever caused the sound, it likely didn't happen in Monroe County. Police and rescue workers scoured the county looking for any evidence of what might have caused the noise after 911 calls started coming in from worried residents.

"Central Dispatch let me know at 12:57 they were getting calls reporting a loud noise, a possible explosion, and they were sending out firefighters and police to check different parts of the county," said Justin Baker, deputy director of the Monroe County Emergency Management Agency.

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"They called me back and said they never found anything. It was heard in Brown, Johnson and Bartholomew counties, too." Baker was at his highway department garage office, where he said loud noises are common so he didn't wonder about the boom when he heard it.

"I do not believe anything happened here," Baker said Wednesday afternoon, as reports spread. "I don't know what happened, but it was some place else geographically."

The American Meteor Society received four reports from people documenting a roaring, booming sound and bright lights between 12:18 and 12:31 Wednesday afternoon. They came from Bloomington, Columbus and two towns in Kentucky, Sadieville and Mays Lick.

The non-profit scientific organization supports astronomy research and keeps track of sightings of glowing meteors, called fireballs, in the sky. The meteor society assigned Wednesday's sightings an event number: 2127-2022.

A Bloomington man said he saw a flash of white light before hearing a "thundering sound" at 12:18 p.m. that he described as being like a canon firing.

A man in Columbus said he heard the sound at 12:20. He reported it lasted 3.5 seconds and was accompanied by two glowing trails of light yellow light.

The people who heard the boom in Kentucky said the sound lasted between 2 and 3.5 seconds. Both reported seeing green trails of light. "It was awesome," the man in Mays Lick commented in his report.

Baker discounted rumors that there had been some kind of ammunition explosion at Camp Atterbury in Johnson County. He spoke to emergency workers in Brown and Johnson counties, and at the military grounds, who reported nothing that would have caused the far-reaching sound.

The Indiana National Guard issued a news release late Wednesday afternoon stating there was no fire, explosion or training activity at Camp Atterbury that would have accounted for the boom.

Jeff Nagan, a public affairs officer at Crane Naval Surface Warfare Center 30 miles southwest of Bloomington, acknowledged the base regularly sets off explosives as part of its weapons disposal work. But he said the sound heard Wednesday did not originate from there.

"Although we had routine ordinance activity at Crane yesterday, March 30, given the wide breadth, scope and timeline of these reports, the noise heard could not have feasibly been from actions at our installation," Nagan said Thursday morning.

Contact reporter Laura Lane at llane@heraldt.com, 812-331-4362 or 812-318-5967.