San Francisco's tallest tower has two mysterious cracked windows. Here's why it could be concerning.

Lynn Yeh/ShutterstockAuthorities discovered two cracked windows at the Salesforce Tower.
  • Authorities discovered two cracked windows at the Salesforce Tower, the tallest building in San Francisco.
  • The tower is less than a block away from the sinking and tilting Millennium Tower, where residents have discovered cracks in the walls and a fissure in one window on the 36th floor.
  • The nearby Salesforce Transit Center remains shuttered after workers discovered cracked beams on the third-floor deck.

Downtown San Francisco’s tall towers are becoming notorious for mysterious cracks in its buildings.

Sometime in the last several weeks, the owner of the Salesforce Tower in the South of Market district discovered two cracked windows in the building – one on the 12th floor and the other on the 14th. The newly constructed skyscraper is the tallest building in San Francisco.

The news of the cracked windows comes just months after workers discovered cracked beams on the third-floor deck of the neighbouring Salesforce Transit Center, which opened in 2018. The center has been closed indefinitely, but plans to reopen.

Read more:
Salesforce moved into a new $US1 billion skyscraper in San Francisco, and the offices are unlike anything we’ve seen

Less than a block away, tenants have also complained of structural issues at the 58-story Millennium Tower, which has been sinking and tilting for about a decade.

In 2015, residents discovered cracks in the walls of the tower’s parking garage and noticed floors that had bubbled up from moisture. Three years later, an apartment owner on the 36th floor discovered a large crack in his window, which authorities said was caused by an “exterior impact.” That same day, residents reported hearing a series of creaking noises, followed by a loud pop.

The engineering firm hired to inspect the window never determined what caused the collision.

Millennium tower Justin Sullivan/Getty ImagesThe neighbouring Millennium and Salesforce towers.

Authorities remain equally puzzled by the latest cracks at the Salesforce Tower, which formed on the interior panes of the windows. The owner, Boston Properties, is now looking into what caused the damage.

A spokesperson for the city’s Department of Building Inspection told the San Francisco Chronicle there was no reason to believe the cracks were related to larger structural issues.

But there’s been some concern about the land shared by all three buildings.

Millennium Partners, the real-estate company behind the Millennium Tower, said construction workers pumped too much water out of the ground while building the Salesforce Transit Center, causing the sand to compress and the tower to settle.

The authority behind the Salesforce Transit Center said the Millennium Tower’s concrete structure should have been anchored to bedrock to support its weight. The tower’s original developer, Mission Street Development LLC, has agreed to perform a nearly $US100 million upgrade to address these safety concerns.

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