San Francisco's $350M Millennium Tower Sank 18 Inches — And It Will Never Be Straight Again

When it opened in 2009, San Francisco's 58-story Millennium Tower was the tallest residential building west of the Mississippi, with penthouses selling for more than $12 million. By 2016 it had sunk about 16 inches and was leaning toward the northwest. The tower sits on reclaimed bay fill and soft Bay Mud. To save money, it was anchored on friction piles driven just 60 to 80 feet into sand instead of 200-plus feet to bedrock. When the neighboring Transbay Transit Center pumped out groundwater during excavation, the sand compacted and the 300-million-pound building began to sink unevenly. A $100 million fix began in 2020, but drilling in 2021 made the tower sink and tilt faster, and work was halted. A scaled-back 18-pile retrofit finally stopped the sinking in 2023. The lean is permanent: the top still sits about 29 inches out of plumb, and units trade at a discount to neighboring towers. Who should have paid: the developer, the transit agency, or the city that approved the plans? Tell me in the comments. #MillenniumTower #SanFrancisco #SinkingBuilding #Engineering #BayArea #Skyscraper #RealEstate