Have you ever operated a forklift? It is incredibly easy to catch a fork or part of the load on something and mangle it to hell. They are made to move huge amounts of stuff with relative ease and those shelves are sturdy, but will collapse if the design is compromised, just like any structure. It's the drivers fault for not checking his path and his load, which is like the third thing they teach you in Forklift drivers ed. Just a week ago, I was using a power jack and accidentally wrecked a pallet when it caught a wall edge and pulled the thing apart in the three seconds it took for me to notice it caught and to bring the jack to a complete stop.

well, that sucks but hey! better that power jack then someone's limb right?

True. I've clipped my foot a couple of times in tight spaces. Hurts like hell.