[Patrick S]

LA and SF are two entirely different beasts. First off, you have to realize the reason that both probably didn't grow up (as in height), especially in SF, is because of the possibility of earthquakes. I say especially in SF because, as I said, they are two different beasts. SF is very densely packed. There are 17,179.2 people per square mile in SF (still not NYC with 27,012.5 people per square mile - with 69,771 per square mile in Manhattan alone), while LA has 8,092 per square mile - less than half. This density is surely lowered by the fact that there is a mountain range that goes right through LA and there is land in the city limits that is not built on. The flip side to that, though, is that there is more land, if they can build on it, in LA and plenty right outside LA (to the north and west) that is undeveloped, that if can be built on could be annexed into the city. The point is that SF is boxed in on 3 sides by water and it is boxed in on the south by other cities. LA still has land (if it can be built on) in both the city limits and right next to it. LA doesn't need to grow up (height) in order to still grow, as much as SF does. Of course, I'm glad they are, but they just don't have to so much. SF, on the other hand, must grow upwards to keep growing, earthquakes be damned.