Gaps inside the walls of the sinking and tilting Millennium Tower are likely the product of its excessive settlement and may pose a widespread fire safety threat, according to a consultant’s findings obtained by NBC Bay Area.

The San Francisco Fire Marshal is expected to visit the building next week to evaluate concerns outlined in a December 2016 analysis of what an inspection showed of one unit in the luxury high-rise.

“This building is not as safe as we’ve all been led to believe,” said Paula Pretlow, who owns a unit on the 31st floor of the 58-story structure that she says has long been plagued by foul odors.

In a December 2016 assessment of the issue obtained by NBC Bay Area, Palo Alto-based building consultants Allana Buick & Bers Inc. trace the odors to openings between the building’s façade, or curtain wall, and the core structure.

The consultants point to the “excessive” settlement as a likely source of the issue, adding, “This condition may be more widespread than these two test areas and may be present in the entire stack. We recommend further investigation of this issue.”

They also issued an ominous warning: “These openings represent a breach in the fire and smoke barrier … which is a life and fire safety hazard to the occupants.”

The threat, experts say, is that not just odors but also smoke and flames can get through those gaps and allow fires to jump floors.

But it took Pretlow a year of fighting to see the redacted findings of the Allana Buick & Bers report, which had been blacked out of the version of the report she was originally given.

Armed with those previously redacted findings, Pretlow made a new complaint to the fire department. Fire department spokesman Lt. Jonathan Baxter confirmed the probe but declined further comment.

The homeowner’s association’s attorney would not talk about the newly emerging issues but did say crews have removed some of the façade panels in light of the consultant’s findings to examine the building further.

The lawyer, Vision Winter, said he couldn’t discuss the matter while the association was still in mediation talks with the Millennium’s developer.

Larry Karp, a geotechnical expert, warns that uneven settlement can wreak havoc and dislodge comparatively light-weight curtain walls, causing a fire risk.

“It’s a huge problem,” Karp said, adding that the curtain walls at the base of the tower would take the brunt of the stress.

“It depends on how they are attached” where the problems will show up, Karp added. “The fact that they are coming apart is inevitable, it’s just a matter of time. It’s going to get worse.”

Millennium officials would not comment for this story, but last month they filed a lawsuit against their Texas-based curtain wall consultant over odor and other wall problems. Curtainwall Design Consulting (CDC) officials did not respond to calls seeking comment.

San Francisco Supervisor Aaron Peskin says the city finally needs to get to the bottom of what is happening at the tower.

“The whole thing is just really disturbing and troubling,” he said, adding that the city’s Department of Building Inspection should be pushing to verify the findings in the 2016 Allana Buick & Bers report.

“Not only do all the condo owners have the right to have that information,” Peskin said, “but the city should have that information, so we can impose the kind of fixes that have to be imposed.”

As if the tilting, sinking and stinking were not enough, Pretlow says her windows are now leaking in the rain – possibly another side effect of the tilting structure. She says she just wants someone to take all the problems seriously.

“This is a serious issue, and I think the city and all parties involved need to recognize it, and something needs to be done.”