not opening on my work comp but i'm pretty sure i know this vid.

that's actually from sympathetic vibration induced by wind, iirc. every object has a frequency that, if it vibrates at that frequency, the vibration waves magnify - instead of ever canceling each other out, they build and build and build until, well, you have a seriously ****in' broken bridge. [can somebody check my physics explanation? i'm just tryin to remember from high school physics here] edit:: vocab word: RESONANT FREQUENCY.

that doesn't mean that steel isn't stiff or strong or any other adjective or characteristic.

cool video though.