Comment by physcab

I'm no civil engineer but I talked to one about this story and the concerns seem to be overblown. First, the foundation as I am aware is created by drilling to the point of refusal. Obviously bedrock is ideal, but in a place like SF where some of the land is based off old landfill, refusal is acceptable. From there a concrete foundation is laid and the building rests upon it. Concrete slabs are secure and in the event of an earthquake it will be allowed to shift and "float" if the ground underneath liquifies. Secondly, the sinking and leaning can be corrected. Engineers account for some level of sinkage as the building settles, and if it tilts, they can apply ties to the sides to straighten it. In the most severe of cases they can shore up the foundation and build more supports. I'm sure the builders are examining their options currently so it'll be interesting to see what course of action they take.