A 58-story skyscraper in San Francisco is sinking and people are fighting over whose fault it is

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Vanguard Properties

Millennium Tower, a $350 million skyscraper completed in 2008, has sunk 16 inches and tilted two inches since it opened.

Now San Francisco’s very own “leaning tower” is in the middle of a battle between the building’s developers, residents, and city officials over who’s at fault. The fight’s far from done.

Here’s what you need to know about the development and sinking of Millennium Tower.


Millennium Tower rises 58 stories above San Francisco’s Financial District.

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Google Earth

The city’s fourth tallest skyscraper contains over 400 multimillion-dollar condo units. It soars 645 feet, providing residents with unparalleled views of the Bay Area.

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Justin Sullivan/Getty

Source: Wikipedia


Completed in 2008, Millennium Tower includes top-notch amenities, including a pool, fitness center, wine cellar and tasting room, and concierge service.

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Vanguard Properties

It’s no surprise that in the first five weeks, Millennium Tower sold $100 million worth of condos, the San Francisco Chronicle reported. The penthouse is currently for sale.

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Wikimedia Commons

Source: San Francisco Chronicle


Some pretty famous tenants have called Millennium Tower home, including former San Francisco 49ers quarterback Joe Montana and late venture capitalist Tom Perkins.

Source: Business Insider


But residents weren’t happy after learning in June 2015 that the building is sinking. It’s sunk 16 inches into soil and tilted two inches to the northwest since opening in 2009.

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Justin Sullivan/Getty

Source: Business Insider


The building’s developers, Millennium Partners, argue that construction nearby is to blame for any sinking or tilting. A transportation hub, the Transbay Transit Center, broke ground next door in 2010, two years after the Millennium Tower was completed.

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Google Earth; Melia Robinson/Business Insider

Source: Business Insider


The new terminal, developed by a transportation agency called the Transbay Joint Powers Authority, includes a 60-foot hole for the train tunnel and an underground buttress between the Millennium Tower and the transit site.

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A wrecking ball takes some of the first swings against the front facade of the old Transbay Terminal building in San Francisco in 2010.
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Eric Risberg/AP

Source: San Francisco Business Times


A founding partner of Millennium Partners says there’s “only one issue” — that construction for the Transbay terminal pumped too much water out of the ground.

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Eric Risberg/AP

Dewatering” is the process of removing groundwater or surface water from a construction site to provide a safe work environment and prevent erosion of the soil.

When the water levels under the Millennium Tower dropped, the sand compressed and caused the building to settle, according to Chris Jeffries, a founding partner at Millennium Partners.

The issue came to light in 2010, five years before tenants were notified, when the Transbay Joint Powers Authority hired a consultant to find out how excavation could affect the tower.


The Transbay Joint Powers Authority maintains it is not at fault for the building’s sinking.

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A rendering of the future Transbay Transit Center shows the terminal’s exterior.
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Transbay Transit Center

The agency released a statement on its website in October condemning the allegations against it as a “distraction from the exclusive cause” of the tower’s tilt: “inadequate foundation.”

The statement also points out that Millennium Tower’s vertical settlement began two years before the Transbay Joint Powers Authority began doing any underground work.


In August, a group of residents filed a class-action lawsuit against Millennium Partners and the Transbay Terminal developers to recover the losses in property value.

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Former San Francisco 49ers quarterback Joe Montana is one of the former tenants seeking damages from Millennium Partners.
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Business Insider

Source: SFist


The San Francisco City Attorney’s office also put Millennium Partners in its crosshairs when it announced in November that it was suing the developers of the sinking skyscraper.

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City Attorney Dennis Herrera gestures while speaking about a lawsuit filed against developers of the Millennium Tower at a news conference in San Francisco.
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Jeff Chiu/AP

The city attorney’s office claimed Millennium Partners failed to disclose that it was sinking to buyers as early as 2009, NBC Bay Area’s Jax Van Derbeken and Jodi Hernandez reported.

City Attorney Dennis Herrera called the situation “every homeowner’s worse nightmare.”


Now the developers of the tower and terminal, city officials, and Millennium Tower residents are asking what could have been done to save the building from its crooked fate.

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Wikimedia Commons

San Francisco supervisor Aaron Peskin kicked up drama in September, when he raised suspicion that city officials knew the building might sink before anyone moved in.

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Aaron Peskin (left) questions city elections director Tammy Haygood about recent election procedures during a supervisor’s rules committee hearing in 2001.
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Eric Risberg/AP

Peskin, who served on the Board of Supervisors from 2005 to 2009 and was reelected in 2015, uncovered documents from 2009 allegedly showing the city’s building inspection department expressed concerns about the tower’s unusual settling to the developers.

Six months later, the tenants of Millennium Tower were approved for move-in.

“I believe, and I know this is a very serious allegation, that there was some level of political interference,” Peskin told reporters on September 13.


There’s also confusion about why the building’s developers were allowed to anchor the building 80 feet into packed sand rather than 200 feet down to bedrock.

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Wikimedia Commons

The Transbay Joint Powers Authority hired a consulting firm in 2010 to investigate the new transit center’s impact on the environment. It found that Millennium Tower’s tilting and sinking wasdue “entirely to the failure of the foundation piles for the Tower to reach bedrock,” according to Scott Boule, a TJPA spokesman.

In other words, the terminal developers blame Millennium Partner for not digging deeper.


The design isn’t all that unusual. Some of the city’s best known buildings, including the Embarcadero Center and SF MOMA, were built on sand instead of bedrock.

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The San Francisco Museum of Modern Art was recently renovated, more than doubling the museum’s exhibition space.
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Eric Risberg/AP

Millennium Tower sits on an array of nearly 1,000 pillars shoved into the ground.

Its own weight combined with the resistance of the soil underneath should keep it in place under most conditions, a professor of architectural design told Curbed.

Source: ABC7


Millennium Tower probably won’t fall, in part because it’s sinking too slowly to take anyone by surprise.

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A certified engineering geologist, right, examines soil samples taken outside the Millennium Tower in San Francisco.
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Eric Risberg/AP

The building’s developers, Millennium Partners, hired engineersto drill holes around the building in order to test soil samples and figure out why the tower is sinking and what can be done to prevent it from sinking further.


The biggest cause for concern is the looming possibility of an earthquake.

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Sewage spreads past a car trapped in a sink hole caused by liquefaction in a New Zealand suburb after a 5.8-magnitude earthquake struck in 2011.
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Simon Baker/Reuters

For years, scientists have warned that the Bay Area is overdue for a devastating earthquake.

Millennium Tower sits on land that is prone to liquefaction, the process by which loose sand and silt behaves like a liquid in the event of an earthquake. The seismic activity causes water pressure in the sediment to increase and grains of sand to lose contact with each other, the US Geological Survey (USGS)explains. The soil may give out under large and heavy structures.

Oftentimes, the solution for tall buildings built in liquefaction zones is drilling down to bedrock. Millennium Tower’s neighbors, the $1.1 billion Salesforce Tower and the luxury high-rise 181 Fremont, are both anchored to bedrock. They’re still under construction.


Millennium Tower will “most likely” sink an additional eight to 15 inches in the coming years, for a total of 31 inches.

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Jerry Dodson and his wife Pat stand inside their home on the 42nd floor of the Millennium Tower in San Francisco.
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AP/Eric Risberg

Source: The San Francisco Chronicle


The “leaning tower of San Francisco” can even be seen sinking from space.

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Data from the Sentinel-1 satellites show that Millennium Tower is sinking by about 40 millimeters a year in the “line of sight” – the direction that the satellite is “looking” at the building.
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European Space Agency