A luxury high-rise in downtown San Francisco has started to gradually sink, and recent satellite images confirm that the problem is growing urgent.
The 58-storey Millennium Tower has already subsided into the soft earth of the busy financial district by 16 inches since its completion in 2009. Satellites from Sentinel-1, the European space agency, have transmitted images that show the skyscraper sinking approximately 40 mm every year. The sinking is not even, resulting in a two-inch tilt at the base of the building and a six-inch lean at the top.
The tower is located in a major earthquake fault zone, creating alarm and turning the situation into a public scandal. Although the cause for the sinking has not been pinpointed, the general belief is that the supporting piles are not sitting firmly on bedrock. Engineers say that there are no immediate signs of the problem stopping.
One tenant noticed something amiss around six years ago while golf putting in her apartment on the 57th floor. The ball kept rolling to the same corner of the room. Other residents soon started wondering if it was safe to stay in the building.
The situation is readily apparent in the underground parking garage, where the walls have floor-to-ceiling cracks, many of them marked by stress gauges to determine growth.
Documents involving the Millennium Tower were recently leaked, such as communications between developer Millennium Partners and the San Francisco Department of Building Inspection. They reveal that both sides were aware of the gradual sinking prior to the building’s opening in 2009, but neither entity made the information public.