Cracks run along the lines of least resistance. They run through material, through concepts and aspirations. Buildings, also conceptual constructs, are assembled of many materials far beyond the visible. What distinguishes the construction and life duration of a building in the conflicted Gaza strip from that of a building in the financial metropolis Tokyo or in hurricane-plagued Florida? Why did the roof of the Berlin Kongresshalle-West collapse? Why that of a sewing factory in Bangladesh? Why geodesic domes in the Californian desert? In retrospect, cracks allow for diagnoses on the essence and the link between ideas and material: in advance, the cracks and predetermined breaking points can only be traced, we can speculate, warn, and mobilize forces, in the hope of avoiding further collapses.