IntroductionCase 1: Before, During and After the Event; the Boeing 747 Case StudyThe Reason for Building such AircraftThe Bijlmermeer CrashCase 2: ERTMS. An Inquiry into the Safety Architecture of High Speed Train SafetyEmergent PropertiesTransparencyTowards a New Train Control ConceptLessons LearnedDiscussionWhat Do We Need to Design Resilient Systems?What has Created Opportunities for Resilience in these two Cases?