DIED. Roberto d'Aubuisson, 48, ultra-rightist strongman linked to death squads during El Salvador's 12-year civil war; of throat cancer; in San Salvador. As founder of the Nationalist Republican Alliance, or ARENA, D'Aubuisson emerged as a hero to wealthy landowners resisting demands for land redistribution and political reforms. His large legion of foes, however, viewed his machismo and ruthlessness as a significant cause of his country's violence, which cost 75,000 lives.