Residents in LaGrange and several western suburbs reported feeling tremors Tuesday afternoon, but authorities are saying all the rumblings probably from blasting at a local quarry.
"We've been calling it probable quarry blasts since early on, so we're not 100 percent sure. We're trying to confirm 100 percent if it was a blast. We have unconfirmed reports that it was mining related," said John Bellini with the United States Geological Survey.
He said the department's instruments pick up "dozens" of quarry and mining-related blasts daily, particularly in the coal belt of the United States.
The so-called "tremor" appears to have hit LaGrange around 1 p.m., and USGS officials initially said it looked to be a 2.7 magnitude earthquake.
At about that time, nearby Hanson Material Services in McCook were blasting, the Chicago Tribune reported. An employee with the company said, however, that the blasting was far away from a residential area and shouldn't have been great enough to be felt.
Another mining quarry near the event is owned by Vulcan Materials, but a spokesman said no blasting was taking place.
"It has nothing to do with us," a manager said when reached by phone.
LaGrange Police Chief Michael Holub said he felt the tremor while eating lunch. He said the department received about 10 calls from concerned neighbors and said there were only a couple reports of very minor damage.
Holub shares the suspicion that the shaking was from a nearby quarry, but said what he felt was powerful than what's typically felt from a blast.
He said the quarry usually gives them a heads up before blasting. In this case, there was no warning.
Residents who felt the tremor, or have identified damage as a result, are asked to contact the Lyons Township Quarry Complaint Line at 1-866-WE-HEAR-U, according to a post on the village's website.
In June, a 5.5 quake near the Canadian capital of Ottawa rattled nerves in Chicago. A 3.3 quake centered near Hampshire, Illinois gave residents from Indiana to Wisconsin a violent awakening in February.