The double-slit interference represents the wave-like properties of physical objects. As one of a few points that founds the quantum mechanics, it is tested over and over in last century. Here we present an example: Auger emission after core excitation in O2. As the result of competition between Auger decay and molecular dissociation, we observed not only the double slit interference, but also the destroy of interference, i.e. evidence for both quantum coherence and its enemy.