Explore the hidden boundaries of safety engineering with Chuck Wolber. This presentation will use practical examples to teach developers how to think about software in a safety critical context. It will identify the limitations of safety engineering and give developers a conceptual foundation for working within those constraints. At the heart of these limitations is the introduction of the "Cinderblock Problem". Chuck will use this problem as a proposed shorthand for expressing the limitations of safety engineering in the context of software design and development.