NEW : USGS revises magnitude down to 3.8 . NEW : ` ` It was so loud An early morning earthquake rattled northern Illinois on Wednesday , shaking an area about 50 miles west-northwest of downtown Chicago , the U.S. Geological Survey said . , I thought a plane had gone down , '' man says . NEW : Quake in Chicago was 3.8 times as powerful . Epicenter was 3 miles from Haiti and 50 miles underground .
NEW : USGS revises magnitude down to 3.8 . NEW : `` It was so loud , I thought a plane had gone down , '' man says . NEW : Quake in Chicago was 3.8 times as powerful . Epicenter was 3 miles from Haiti and 50 miles underground .