Pulse interaction with a partially contacting plane of weakness (interface) is investigated experimentally as well as numerically. The interface is subjected to static pre-stresses. Using dynamic photoelasticity in conjunction with high speed cinematography, the evolution of the dynamic interaction is recorded by means of isochromatic fringe patterns (contours of maximum shear stress). It is shown that interface slip can be triggered by a pulse that propagates along the interface at the relevant Rayleigh wave speed. Numerically, a finite difference wave propagation simulator SWIFD is used to discuss dynamic rupture in laterally heterogeneous structures by considering the effect of acoustic impedance mismatch. The results indicate that upon interface rupture, Mach waves, which carry a relatively large amount of concentrated energy, can be generated and propagated off the interface contact region (asperity). Such Mach waves can cause concentrated wave-induced damage in a particular region. It is possible that the “damage belt” found in Kobe. Japan, on the occasion of the 1995 Hyogo-ken Nanbu earthquake, was generated by Mach waves.