NiTi based shape memory alloys (SMAs) show fascinating functional properties. They are able to re-establish their initial geometries after deformations which significantly exceed conventional elastic strains. The service lives of SMAs are limited by functional and structural fatigue. Functional fatigue refers to the transformation-induced formation of defects and results in a degradation of exploitable shape memory strains and changes in transformation temperatures. In contrast, structural fatigue describes the formation of cracks during dynamic loading. Today, a good understanding on surface- and microstructure-related effects on fatigue lives, crack formation and macro-crack growth of SMAs has been established. However, the present knowledge on micro crack growth is very limited. In the present work, we study short crack growth in pseudoelastic NiTi SMA wires using interrupted bending rotation fatigue (BRF) experiments. After specific number of BRF cycles, the wires surfaces were investigated in the scanning electron microscope to track the growth behavior of specific individual cracks. Our results show that only a small number of cracks manages to evolve into macroscopic cracks. For the first time, we document how individual micro cracks interact with microstructural constituents and other cracks.