The talk takes a deep-dive into the Abbeystead explosion (using pretty much all available sources available on the subject), one of the worst civil engineering disasters in post-war history, through the lens of the HSE investigation. It looks at what the project was for, how it was designed, what went wrong, and why. Swiss cheese is a way of conceptualizing accidents, and the explosion is used so show how this works. Hopefully by the end, everyone will have heard about a facinating case study in bad project management, weird critical infrastructure, and have recieved a safety talk by stealth.