Great link! But If you zoom in, you'll see the Marina, South of Market, and the edges in NB etc are "red" (the worst areas). This is exactly why the financial district (where the high-rises are) is located where it is (on Yellow to montgomery), and why SOMA was the "wrong side of the tracks". While they are/have been recently building high rises in the Red (embarcadero, etc), they have been digging 150 feet down (ie, 2x the normal height of an above-grouhnd building ~traditionally < 7 stories). to set the foundations. At least that's my understanding.