As would I. But a crack is an absence, where the substrate has dislocated apart. I suspect that anything.not being actively progressively driven apart by a separate (locally-supersonic) additional thing (e.g. a supersonic (even hypersonic, wr.t. air) penetrating projectile, or by the detonation of a faster-propogating explosive material prepared as an intrusion already... either of which I would say are cheating in this scenario) is entirely dependant upon how quickly one atom in the (amorphous?) mass is sufficiently displaced by the prior atom(s) having been displaced, which has its limit to something like that of the internal "speed of sound".
Obviously if you strike the first atoms enought to excite them onwards at 'unnatural' velocities into the next atoms, it'll be like the penetrator, but as soon as the effect translates to cracking (especially lateral displacement, breaking any high-tension bonds and allowing high-compression bonds to get their desired breathing space) the 'information' speed limit is essentially sonic-limited. Or, rather, sound in the material is just the same thing but (usually) beneath the failure/assymetric stress relaxation level.
But I'm more familiarvwith metals, and laminated glass poses kther issues (does the lamination-bonder effectively act as a 2D molecule, chanelling failure-level stresses faster, in its own higher-than-glass 'local' speed of sound, and the propogation decays inversely rather than inverse-squaredly, as a price to be paid for having up until then withstood far more stress than the unlaminated equivalent glass). And if it's more that 'soake up' overdamage finally gets released by the final criticality of failure, the question still remains how the coordinationis achieved to fail (apparently sequentially) at a rate of inter-zone 'messaging' that exceeds the usual force-transfer. (Possibility: the molecular forces trip' the next atom along, not just the adjacent one, because of the extraordinary crystal-breaking effect. But I can't see it being coherent enough to trigger an 'unzip', at best an audio version of Cherenkov Radiation just... doing I don't know ehat.)
((Not claiming Materials Science expertise on this one. Not if it gets beyond your basic metallic ductility, anyway. Just my first thoughts on the subject.))