Hurricane Katrina was one of the worst disasters in United States history. Failures within New Orleans' engineered hurricane protection system (levees and floodwalls) contributed to the severity of the event and have drawn considerable public attention. In the time since Katrina, forensic investigations have uncovered a range of issues and problems related to the engineering work. In this article, my goal is to distill from these investigations, and the related literature that has accumulated, some overarching macro-ethical issues that are relevant for all engineers. I attempt to frame these issues, using illustrative examples taken from Katrina, in a way that might be of pedagogical use and benefit for engineering educators interested in engaging their students in discussions of engineering ethics, societal impact of engineered systems, engineering design, or related topics. Some of the issues discussed are problems of unanticipated failure modes, faulty assumptions, lack or misuse of information, the importance of resiliency, the effects of time, balancing competing interests, attending to the details of interfaces, the fickleness of risk perception, and how the past constrains the present.