A new report suggests a fire risk inside San Francisco's leaning, sinking skyscraper

Millennium Tower, a $US350 million skyscraper completed in 2008, has sunk 16 inches and tilted two inches since it opened.

A new report indicates that might not be the worst of it. An outside architecture engineering firm found gaps in the walls of one unit that could present risks in the event of a fire, NBC Bay Area’s Investigative Unit reported.

Late in 2016, the building’s homeowner association hired firm Allana, Buick and Bers to investigate a unit owned by Paula Pretlow. Pretlow and several other residents complained in the past of “unexplained odours permeating their luxury units,” NBC Bay Area reported.

The consultants burrowed holes through several apartment walls in Pretlow’s unit and set off smoke bombs below. They found that smoke rose through openings surrounding pipes and ducts. Typically, gaps like these are sealed with fire-resistant caulking to make sure fires are contained on the floor where they start.

If a small fire was to break out in the unit below where Pretlow lives, the flames could more easily spread to her condo or cause smoke damage in the walls, according to NBC Bay Area.

John Darmanin, a retired San Francisco fire captain, told NBC Bay Area that it’s the developer’s job to ensure all gaps are propertly protected against fire. But city inspectors are also tasked with checking those seals during construction.

The report only pertains to the unit owned by Pretlow, though others may be susceptible.

“Did someone have a bad day that day? Let’s hope,” Darmanin said. “But if there are other units that are complaining of odours, and no one is investigating because they are afraid of what they might find out? I have a real problem with that if I’m a tenant or if I’m in the fire department.”

In January, an investigation by the city’s Department of Inspection concluded that the skyscraper is safe to live in. Millennium Tower is likely to continue to sink at a rate of two inches per year — double what engineers earlier estimated, according to an AP report.

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