JANESVILLE - What caused the window-rattling rumble that shook parts of southern Wisconsin on Sunday evening and lit up social media sites with speculation? Everyone wanted to know the source of the sound they heard at about 8:15 p.m. People reported hearing a roaring sound that lasted between one and three minutes. It was heard in Janesville, Beloit, Milton, Evansville, Albany, Monticello, Monroe, Elkhorn and Delavan, among other communities, according to Facebook comments.