The National Weather Service confirms a tornado did touch down in Rock County this week.  The weather service says the tornado blew off the roof one building about six miles northwest of Beloit just before 7:00 p.m. Wednesday.  Other reports included downed trees and damage to a sheet metal roof and at least one vehicle.  The weather service says the storm included winds of up to 75 mph and tracked for three-and-a-half miles.  At one point the twister was 50-yards wide and stayed on the ground for ten-minutes.  The tornado is classified as an EF-0.