Published time: 26 Apr, 2018 16:25 Edited time: 26 Apr, 2018 16:43 An explosion and fire at the Husky Energy oil refinery in Superior, Wisconsin, has resulted in at least 20 casualties, according to the Superior Fire Department. “There is a report of multiple casualties. Initial reports are at least 20 casualties transported. Multiple agencies have responded,’’ said Superior Fire Chief Steve Panger in a statement. Reports of an explosion and fire at the refinery emerged just after 10am on Thursday. Huge plumes of black smoke could be seen emitting from the Stinson Ave. location. Witnesses reported feeling the shaking of an explosion, soon after employees were evacuated and emergency services were on the scene. At least seven ambulances are on the scene, several of which have already left with victims, reports the Duluth News Tribune, while emergency helicopters are also on standby.