The aim of this paper is to explore whether and how far organisations learn from failures. Methods: The paper reviews the current literature about organisational learning and theories of learning from failures, where learning here implies change of practice, and use of modelling techniques to inform recommendations to prevent repetition of similar incidents. Further, it analyses two case studies related to aspects of security and safety: the Virginia Tech Shooting in 2007 and the Lion Air 610 crash in 2018. Both case studies address the concept of learning from failures. In doing so, an analysis of the root causes and vulnerabilities through the methods of Fault Tree Analysis and Reliability Block Diagram is conducted to identify lessons to be learned. Results: Findings are intended to stimulate organisational learning and improve organisational processes to mitigate disasters from happening again. Conclusion: The value of this study is that aspects of learning and unlearning from failures have been identified for the cases used. Expectation for future studies is to extend the proposed methodology to other cases in the fields of surveillance, security and safety.