I recall seeing some computer animation to this effect in a documentary (in the UK) about the Millennium tower tilting - searching on that brought up some confirmation in the form of a press release by the TJPA:
The 60-story Millennium Tower is made of concrete rather than steel, resulting in a very heavy
building. This heavy structure rests on layers of soft, compressible soil. The foundation of the
Tower, however, consists only of a concrete slab supported by short piles that fail to reach the
bedrock below. That foundation is inadequate to prevent settlement of a building with the weight
of the Tower. In contrast, the Salesforce Tower and 181 Fremont Tower, also adjacent to the
Transit Center, are supported on piles drilled down to bedrock. Millennium Partners’ poor design
decision is the cause of the tilt and excessive vertical settlement of the Millennium Tower.
Sure, at about the 20:00 is when they discuss Mission Bay specifically. The whole documentary is solid though if you have more time. I learned a lot and found it very fascinating.
That’s how it was explained in a documentary about mission bay (south of AT&T).
edit: For those interested, this documentary explains the approach https://www.youtube.com/watch?v=SyjijQS2dAk&t=1219s