The paper examines supply chain risk management with a particular focus on supplier default risks, using Toyota’s response to the 2011 Tohoku earthquake as a case study. It begins by discussing the increasing prevalence of major supply chain disruptions, driven by factors like climate change, extreme weather, natural disasters, and unforeseen events such as the Covid-19 pandemic. These disruptions have highlighted the unpreparedness of many companies, which often resort to ad hoc measures. The study emphasizes the need for comprehensive risk assessment and mitigation strategies to enhance supply chain resilience. It reviews current research in supply chain risk management and analyzes how Toyota managed the challenges following the supplier defaults caused by the Tohoku earthquake. The paper concludes by comparing practical case study results with theoretical findings and offers insights for future research in risk management and supply chain resilience.