Only 18 days away from the 10th anniversary of the worst terrorist attack in American history, Madison on Wednesday is quietly commemorating the 41st anniversary of one of its darkest days: the bombing of Sterling Hall on the UW campus. Early in the morning of Aug. 24, 1970, four anti-Vietnam War radicals ? Karleton Armstrong, his brother Dwight Armstrong, David Fine and Leo Burt ? used a van filled with almost a ton of ammonium nitrate and fuel oil to bomb Sterling Hall, killing researcher Robert Fassnacht and injuring three others.