The science of complex systems is a relatively new field that tries to understand the nature of systems that were up to now thought to be way too complicated to be accessible to science. These systems include eco-systems, societies, financial markets, or cities. In combination with big data for the first time it becomes possible to understand relevant properties of such systems, such as their efficiency, their resilience and robustness. An issue of particular importance is that complex systems collapse. A scientific understanding of the nature of collapse could become relevant in understanding under what conditions systems collapse and how to avoid it.