Millennium Tower Lean: When Foundation Design Becomes a Legal Fault Line The Millennium Tower in San Francisco has sunk over 18 inches and leans nearly 29 inches due to reliance on friction piles in soft clay instead of deep bedrock anchors. This foundation design choice led to differential settlement, triggering lawsuits over construction defects, disclosure failures, and professional negligence. Expert witnesses in geotechnical engineering, building design, and real estate valuation played a central role in identifying liability and assessing long-term consequences—making the case a landmark example of how early design decisions can lead to high-stakes litigation.