The Fond du Lac Fire Chief says the natural gas explosion in Sun Prairie shows how dangerous gas leaks can be. Fire chief Pete O’Leary says its important for residents to call immediately if they smell natural gas or suspect there may be a gas leak. O’Leary says it will probably be several days before its safe for Sun Prairie residents in the immediate vicinity of the explosion to be able to return to their homes and businesses. Meanwhile, the Fond du Lac Fire Department responded to a gas leak Wednesday at a residence on Star Street. A construction crew hit a residential gas line while while drilling for new gas service.