Notorious 58-story luxury high rise has already sunk significantly and tilted 18 inches since it was completed in 2009

It’s not often that a broken window makes international news, but this is not just any window. It’s a window on the north-west corner of the 36th floor of San Francisco’s most notorious building – the sinking and tilting Millennium Tower.

Residents of the luxury condominium tower – which was once better known for its multi-million dollar views than for its multi-hundred-million dollar engineering woes – were reportedly alerted to the fissure by a series of creaking sounds followed by a loud pop at 2.30am Saturday.

The culprit was “a large piece of glass that cracked on the exterior of the building this weekend on the 36th floor”, the building’s general manager, Michael Scofield, told residents in an email seen by the Guardian.

Potentially more ominously, Scofield added, “it is possible that this incident is related to other issues in the building”.

Issues faced by the building include the uneven and unexpected settling of the 58-story high-rise, which has sunk significantly deeper than projected since it was completed in 2009 – and tilted 18 inches to the north-west. All of that sinking and tilting has resulted in cracks in the sidewalk and basement and unleashed an ugly and litigious blame game between homeowners, the building’s developer, the city of San Francisco and a neighboring construction project.

Scofield did not immediately respond to a query from the Guardian, but building management appears to be cooperating with San Francisco’s Department of Building Inspections, which issued a citation on Tuesday requiring management to investigate and correct the situation. An engineering report assessing the cause and any concerns about the building’s adjacent curtain wall is due by the end of Friday.

Steven Mayer, a resident of the building and president of the homeowner’s association, seemed unruffled by the latest problem to strike the tower.

Right now it appears to just be an anomalous situation of a window cracking, but we are going to do additional inspection Steven Mayer, president of the building's homeowner's association

“Right now it appears to just be an anomalous situation of a window cracking, but we are going to do additional inspection,” Mayer said. “We don’t know for certain.”

Another resident, Jerry Dodson, was less sanguine, telling NBC Bay Area: “It’s an alarm, and it has made people in the building nervous. At this point we need a report from the city as to what’s going on. I think with a building that is sinking, tilting and twisting, it shouldn’t be a surprise to anyone that you have failures in the building.”

Aaron Peskin, a member of the city’s board of supervisors who has held a number of hearings on the building’s problems, said that the window crack was “a serious concern”.

“These window systems are designed to withstand hurricane force winds and are not supposed to fail in large seismic events,” he said. “The question is whether or not the sinking and tilting are creating stresses on what is called the curtain wall … Is this a one-off incident or is this part of a systemic failure of the curtain wall, in which case, that’s very, very dangerous.”

In the meantime, the city has cordoned off an area of sidewalk below the cracked pane, and Mayer is not losing much sleep about either the window or tilting.

“The key thing is that we have been identifying engineering solutions that are practical,” he said. One plan would involve drilling hundreds of feet below the building to reach bedrock and stop the sinking – but only on one side of the building. Engineers would then wait until the other side of the building had sunk enough to even out the tilt, then anchor that side as well.

“The engineering is moving forward very nicely, and the litigation and mediation processes are looking to bring the parties together to fund the repairs,” Mayer said. “For me personally, I feel very comfortable in the building. I think the building is really solid and well built.”