SAN FRANCISCO (KGO) -- Another lawsuit was filed Tuesday because of the sinking and tilting downtown San Francisco high-rise, Millennium Tower. This legal action might be the most important one of all.
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The lawyer for the Millennium Tower Homeowner Association says their goal is to make sure that the residents, many of whom invested their life savings to buy a home in the building, get the just value of their purchase.
"Who knew what and when, and why didn't they tell the homeowners," asked Millennium Tower Homeowners Association lawyer Daniel Petrocelli.
It's the $64,000 question, and in this case, it'll undoubtedly be more. But that's what the homeowner's association of the Millennium Tower wants to find out through their lawsuit.
They're suing the developers, Millennium Partners and just about everyone else who built the nearly 60-story, downtown high-rise, which has unexpectedly sunk 16 inches and tilted several inches to the Northwest.
In a previous story, a golf ball could be seen rolling down the uneven floor ofa resident's 42nd-floor unit.
RELATED: San Francisco inspectors say millennium tower safe to occupy
Others have also filed lawsuits, some residents, and even city attorney Dennis Herrera.
But under the law, the homeowner's association lawsuit is the only one that can address the structural issues of the building.
"Our goal is to recover all the funds that are necessary to fix this building and fix it once and for all," said Petrocelli.
The HOA is also suing the Transbay joint Powers Authority, which is building a huge transit complex next to the tower. "Their work on an adjacent site to the tower may have contributed to the problems," Petrocelli told ABC7 News.
It's the same charge that the developers Millennium Partners are making, that the tower's groundwater level dropped by a staggering 20 feet when the TJPA built an underground buttress wall between the building and its transit site.
Whatever the cause of the structural shifting, the homeowners board says it's been difficult for many of the 1,000 residents.
WATCH VIDEO: Luxury skyscraper Millennium Tower sinking in downtown SF
"As one person said, something's been taken away from them," said Millennium Tower Homeowner's Association President Steven Mayor. "We want them to have the value back that they justly deserve, so they can live the lives they want to."
The city of San Francisco is not a defendant in the lawsuit, but the lawyer filing the suit says they can add defendants at any time. Aaron Peskin said the city inspection department may have known about the sinking and tilting of Millennium Tower before the first unit was ever sold.
Click here for more of our stories, photos, and video on Millennium Tower.
Millennium Partners, developer, host of others sued by homeowners