Report: Tremor felt across Chicago area was a quarry blast, not earthquake
McCOOK – An official from Hanson Material Service said a blast occurred at its quarry in McCook shortly after 12:30 p.m. Monday.
"We did blast, but the matter is under investigation, so I can't comment any further," he said.
The blast, initially labeled a 3.7 magnitude earthquake by the U.S. Geological Survey's National Earthquake Information Center before being changed to a 3.2 magnitude quarry blast, was felt across the Chicago area.
"We're pretty sure it was a quarry blast," said Paul Caruso, a geophysicist with center, "but there's still controversy."
Caruso said the tremor was felt as far as Kenosha, Wisc. The U.S. Geological Survey website indicated the tremor originated in Countryside. Hanson's quarry is located at 9101 W. 47th St. in McCook.
A 3.2 magnitude tremor is considered light and does not typically cause damage, according to the U.S. Geological Survey website.
Social media accounts of users across the western suburbs became active following the blast, with reports of the tremor being felt from Berwyn to Downers Grove.
"Indian Head Park, most definitely," Facebook user Jane Nelsen reported on the Suburban Life's Facebook page. "I live in Wilshire Green and could feel the whole building shake."