Source of mysterious explosion in Illinois sought

24 February 2007: Police from at least three municipalities searched for the source of a loud explosion heard in and around McHenry, IL, located about 15 miles south of the Illinois-Wisconsin state line and about 20 miles west of I-94 at about 8:30 p.m. Friday evening. Residents in the area of McHenry heard a large explosion - strong enough to shake houses in the area, and at least one resident observed a plume of smoke in the distance, but police from three departments failed to find anything after a search of the area. Police from McHenry, Johnsburg and McCullom Lake helped in the search.