1. Destroyed as in it looks like a wild fire went through it. What's left of buildings is twisted and distorted, like it's been burned. (Though not literally, so there isn't any ash or anything.) The objects within the zone basically shriveled up because the energy got sucked out of them.

2. Once or twice a month in slow periods, or once every week or two when it's busy. Of course, you also may end up with two games dropping in the same day, so you always have to be on guard.