Sorry, forgot to mention Jericho. Did you know, that from the Roman times, to this day, soldiers marching across bridges go into what is called "route step"? The reason is that soldiers marching in cadence can cause a resonant frequency (critical frequency), to de-stablize te bridge's structure, which would cause the bridge to collapse... There are lots of examples of just that happening, as well as video footage of the wind (small wind), causing the same resonant frequency to collapse a bridge in the Tacoma narrows in the 40s. I think they knick named the bridge "Galloping Girdie".