Workers scramble to fix San Fran's Millennium Tower as luxury building continues to sink

The Millennium Tower in San Francisco is sinking, which is causing it to tilt to the west, despite the efforts of workers scrambling to attempt to fix the problem with the luxury high rise.

According to reports, the tower is currently leaning more than 29 inches at the northwest corner, with much of that lean occurring during the digging phase of the plan put in place to eventually support the tower along its sides. 

Engineers saw signs of progress earlier this year when six concrete-filled steel pilings were implemented along the base of the $350million building, but that effort may have led to the new amount of tilt assumed by the sinking tower that was built on a former landfill.

The result of the lean has been leaking and crumbling walls in the facility's below-ground parking garage, while residents live above. 

Workers repair crumbling walls that have been the result of leaking water in the garage of the Millennium Tower in San Francisco

Engineers running the project now claim that data implying the tilt has increased may not be reliable, despite previously relying on it to support their claims of early success with the project. 

The lead engineer of the project, Ron Hamburger, told NBC  the data taken from rooftop measurements are prone to weather fluctuations and that data taken from the building's foundation is more reliable.

Data from the building's foundation also indicates that the current tilt is more significant than previously noted, though only by about a quarter of an inch, an amount Hamburger claimed was 'negligible.'

'We are fully confident that following transfer of the remaining design load to the piles,' said Hamburger, adding that 'there will be no further … movement of the roof to the west.'

Hamburger said he and his team next plan to secure the foundation of the building to 12 pilings sunk along Fremont Street that will bear the partial weight of the building load.

Veteran geotechnical engineer Bob Pyke, who has long been a doubter of the $100million plan to fix the leaning tower, feels considerably less optimistic about the next stage of the project.

'As far as remedial work goes, this is just a mess. You spend all this money, but you still have an uncertain result long term,' he said.

Pyke says there is no way to know if fixing the tower will work as hoped and stop tilting after some of its weight is shifted to the piles rooted in the bedrock.

'The design team has always claimed that there is going to be some rebound after they connect the perimeter piles. So far the evidence seems to suggest that’s not going to happen,' he said. 

The plan as it stands at the moment is to have the building load partially shifted to those piles inside of the next several days.

The effort to stabilize the building and stop the sinking and leaning has been going on since the spring of 2021.

Millennium Tower on Mission Street in San Francisco's Financial District. The building opened in 2009 and by 2016 had sunken 16 inches

A stress gauge is seen on a wall with floor-to-ceiling cracks in the parking garage of the Millennium Tower

A stress gauge on the wall of the tower's storage area, where floor-to-ceiling cracks developed

By 2016, the building (to the right of the tallest building) had sunk nearly a foot-and-a-half into the soft soil and landfill upon which it was built. Residents of the building subsequently sued the developer and designers

The luxury 58-story tower opened in 2009 and quickly sold out its 419 apartments, with buyers including former San Francisco 49er Joe Montana and former Giants outfielder Hunter Pence. 

By 2016, the building had sunk nearly a foot-and-a-half into the soft soil and landfill upon which it was built in San Francisco's financial district.

It was also leaning, creating a two-inch tilt at the base, and a 6-inch lean at the top. Residents of the building subsequently sued the developer and designers. 

A confidential settlement reached several years ago included $100million to install 52 concrete, 140,000-pound piles to anchor the building to bedrock located 250 feet below ground, with the idea that the piles would provide foundational support to the leaning, sinking tower.