SAN FRANCISCO―The San Francisco Millennium Tower has sunk twice as much as previously expected, the European Space Agency has reported.

The San Francisco skyscraper sunk 16 inches since its completion in 2009, according to the ESA. The building has a visible slant, drawing some residents to dub the skyscraper the ‘Leaning Tower of San Francisco’. The ESA reported that the Millennium Tower has been pushed back six inches since 2009.

The ESA used their Sentinel-1 satellites to observe the building’s changes on Thursday, November 24.  

Over a one year period, the Tower has reportedly sunk almost 1.7 inches. Following a 17-month observation period, the Tower was reported to have sunk an additional 2.8 inches.

Millennium Partners, the building’s developers, first announced that the building was sinking in August 2016. A report from engineering firm, Simpson, Gumpertz & Heger stated that the building was safe for residents despite its current sinking and leaning issues.

“We conclude that the settlements experienced by the 301 Mission tower have not compromised the building’s ability to resist strong earthquakes and have not had a significant impact on the building’s safety,” the report states.

Despite the engineering firm’s report, San Francisco City Attorney Dennis Herrera filed a lawsuit against the developers claiming they did not tell buyers the tower is sinking “much faster than expected.”