USGS says Chicago’s western suburbs hit by quake

USGS says Chicago’s western suburbs hit by quake
Scientists of the U.S. Geological Survey say it’s likely it was an earthquake that shook Chicago’s western suburbs after a blast at a quarry. USGS scientist Jim Dewey says research indicates quarry blasts don’t cause larger follow-up tremors. However, a quarry blast in McCook was followed by a related tremor seven seconds later.