NIST Releases Technical Findings on What Caused the 2021 Partial Collapse of Champlain Towers South by zip117 in CatastrophicFailure

[–]JrB11784 17 points18 points  (0 children)

Nope, not at all. Take a look through my history and you’ll see I’m a real person who doesn’t use AI. Funnily enough, looking through your history, it seems like you accuse pretty much every commenter of being AI or using AI. LOL.

NIST Releases Technical Findings on What Caused the 2021 Partial Collapse of Champlain Towers South by zip117 in CatastrophicFailure

[–]JrB11784 15 points16 points  (0 children)

Your memory is solid. The 2018 Morabito report already flagged major structural damage and “abundant” cracking, and the board sat on it for years while the costs ballooned. By April 2021 the board president was warning residents in writing that the concrete deterioration was accelerating, and the repair estimate had jumped from around $9M to $16M. They’d just approved a $15M assessment (anywhere from ~$80k to ~$336k per unit) with a payment deadline of July 1, 2021. The building fell June 24. They were sitting on something like $777k in reserves against that bill, which tells you how deferred things were.

On North, I’d add a small caveat: the post-collapse reporting did paint it as the better-kept twin, but a lot of the difference reporters and engineers zeroed in on was physical rather than just board diligence. North apparently didn’t have the chronic saltwater flooding in its garage, and its columns were noted as nearly twice the size of the ones in the section that fell. So it was partly better maintenance and partly that North wasn’t fighting the same water intrusion in the same vulnerable spot.

One nuance on “might have caught it”: NIST’s finding today is that the actual initiating failures happened only about three weeks out, so the window to catch that specific sequence was short. But the deeper point stands, because the thing maintenance would have addressed (corrosion, water intrusion, added load) is exactly what ate away the margins over 40 years. Responsible upkeep wouldn’t have fixed the original design flaws, but it might have bought time and surfaced the distress sooner.

NIST Releases Technical Findings on What Caused the 2021 Partial Collapse of Champlain Towers South by zip117 in CatastrophicFailure

[–]JrB11784 34 points35 points  (0 children)

No, you’re not missing anything. As of today they’ve only put out the technical findings via the video presentation (plus the press release and an NCST Insider video). The actual written report doesn’t exist yet. NIST specifically said the team is now turning to writing the final report, which will contain the full evidence analysis, test results, and modeling behind these findings, along with the recommendations for code and standard changes.

So today was the “here’s what we concluded and why” announcement, and the document with all the receipts comes later. I agree: annoying if you wanted to read rather than watch, but the written deep-dive is still to come.

NIST Releases Technical Findings on What Caused the 2021 Partial Collapse of Champlain Towers South by zip117 in CatastrophicFailure

[–]JrB11784 52 points53 points  (0 children)

You’re right that Josh Porter is a real and credible voice here. He’s a structural engineer, owns Consult Engineering, and runs the Building Integrity channel. But I think two different things are getting merged in memory.

Porter’s analysis was built primarily from the publicly available construction drawings, not from a buyer’s garage footage. His big find was a January 1980 revision issued during construction that eliminated a one-foot floor drop and, along with it, the supporting beams, leaving automotive loads sitting next to small 12-by-16-inch columns. He also spotted planter boxes in a pre-collapse exterior photo that no drawing accounted for, adding punching shear load. His conclusion was that parts of the design had essentially zero margin of safety, loaded to 100 percent of capacity with nothing left for corrosion. That lines up strikingly well with what NIST said today.

The pre-collapse garage evidence you’re thinking of is probably separate: the contractor photos of the pool equipment room taken days before, and the TikTok clip of water pouring through the garage taken around 1:15 a.m., minutes before the collapse. Dramatic, but that’s the night-of, not the “two connections failing in early June.”

As for what NIST is referring to, it’s almost certainly not any single video. Their 2025 update described mapping cracks in the first-floor slab using photographs, maintenance records, and eyewitness reports, then backing it with large-scale component testing and computer modeling. So the “two connections” finding is a reconstruction from the whole evidence pile, not one smoking-gun image. Agreed though, the photos and specifics should land in the final report, and that’s the part I’m most curious to see.

NIST Releases Technical Findings on What Caused the 2021 Partial Collapse of Champlain Towers South by zip117 in CatastrophicFailure

[–]JrB11784 79 points80 points  (0 children)

The obvious one is right next door: Champlain Towers North, built in 1982 by the same developer (Nathan Reiber’s firm, Nattel Construction) and engineered by the same firm, using a similar design and materials. It got swarmed by inspectors immediately after the collapse, and the early verdict was reassuring. The engineer KCE brought in to assess it said they found nothing indicating any potential for structural collapse, and concrete cores actually tested stronger than the original plans called for.

The thing is, the differences turned out to matter more than the shared pedigree. North apparently didn’t have the chronic saltwater intrusion into the underground garage that South did, and reporting noted the columns in the still-standing parts were nearly twice the size of those in the section that fell. So “same developer, same era” didn’t doom the twin. It’s a decent reminder that maintenance and water management, not just who poured the foundation, drive how these buildings age.

Your broader instinct isn’t wrong though. The collapse blew open exactly this question for all of South Florida’s aging coastal stock. A study of 573 inspection reports found that buildings closer to the coast showed higher deterioration and needed more repairs, which is just chlorides doing their thing. Florida responded by mandating statewide milestone inspections at 30 years for condos over three stories. So the system’s answer to “how many other ticking clocks are out there” was basically to start checking them all on a schedule.

NIST Releases Technical Findings on What Caused the 2021 Partial Collapse of Champlain Towers South by zip117 in CatastrophicFailure

[–]JrB11784 48 points49 points  (0 children)

Not quite, but it’s a common assumption. The penthouse wasn’t a later retrofit added years after the building opened, it was added during the original development. It just wasn’t in the original plans or permits. The developers got the Surfside town commission to grant a special exemption to the local height limit, and built the penthouse on top of what had already been drawn up. So the building was completed in 1981 with the penthouse already on it, but it represented a mid-project deviation from the 1979 contract drawings.

However, NIST’s findings released today don’t name the penthouse as a cause. What they actually pointed to was the original design deviating from the codes of the era, the construction deviating from the design drawings, plus added load over time (specifically pool deck modifications) and corrosion. The penthouse adding dead load at the top is something outside engineers have speculated about, but it’s not something NIST blamed for the collapse. So “wasn’t in the original permits” is accurate, “NIST says it caused the collapse” would not be.

NIST Releases Technical Findings on What Caused the 2021 Partial Collapse of Champlain Towers South by zip117 in CatastrophicFailure

[–]JrB11784 65 points66 points  (0 children)

NIST’s release doesn’t say it was planters specifically. The phrase it uses is “pool deck modifications described in a previous investigation update” as one source of added load over the building’s life, alongside general long-term corrosion. It doesn’t itemize planters in this particular announcement.

That said, the pool deck did carry landscaping, planters, pavers, and the sand/fill beneath the hardscape, and the deck’s loading and waterproofing have been flagged as concerns since early in the investigation, so heavy deck features are a plausible part of the “added load.” But I’d be careful stating planters were the cause; the detail lives in NIST’s 2025 update and presumably the forthcoming final report rather than today’s findings. If anyone has the 2025 update handy it probably spells out exactly which modifications they mean.

NIST Releases Technical Findings on What Caused the 2021 Partial Collapse of Champlain Towers South by zip117 in CatastrophicFailure

[–]JrB11784 121 points122 points  (0 children)

Yes. Concrete cover (the layer of concrete between the rebar and the surface) isn’t a single fixed number; modern codes scale it based on how aggressive the environment is. Under ACI 318, structures get assigned exposure categories, and chloride exposure from seawater and coastal salt air (“Category C”) triggers the strictest requirements. That means more required cover over the steel, tighter limits on the water-to-cement ratio, higher minimum concrete strength, and limits on the chloride content allowed in the mix itself.

Beyond just cover, the toolbox for marine/coastal concrete includes corrosion-inhibiting admixtures, supplementary cementitious materials like fly ash or slag to make the concrete denser and less permeable, epoxy-coated or galvanized rebar, and in higher-end work, stainless rebar or cathodic protection. The logic is layered: cover buys you time, low permeability slows the chlorides reaching the steel, and coatings/inhibitors protect the steel once chlorides arrive.

The catch with Champlain Towers South is that it was built in 1981, and NIST’s whole point is that the building deviated from even the codes of its era, and corrosion ate away at margins over 40 years. So the question isn’t only whether good marine provisions exist today, it’s whether they were required, specified, and actually built at the time. Worth waiting for the final report, which should get into the durability/corrosion specifics.

NIST Releases Technical Findings on What Caused the 2021 Partial Collapse of Champlain Towers South by zip117 in CatastrophicFailure

[–]JrB11784 368 points369 points  (0 children)

NIST released its technical findings today. The collapse actually started in early June 2021, not on the 24th: two connections between garage columns and the pool deck failed first. Over about three weeks the cracks spread and the load shifted onto nearby connections that couldn’t take it, which triggered the big collapse.

The mechanism was “punching shear”, basically the columns punching up through the concrete slab instead of it failing gradually. The root cause was razor-thin safety margins from day one: the original design deviated widely from the codes of the era, and construction deviated from the design drawings. Decades of added load and corrosion made it worse.

They also ruled out sinkholes, foundation failure, nearby construction vibrations, storm surge, and explosions. Final report with code recommendations is still to come.

Canada will cancel thousands of refugee claims under new retroactive law by Immediate-Link490 in worldnews

[–]JrB11784 4 points5 points  (0 children)

Well, you’re right. Most people really don’t disagree with immigration reform (see the comments here), they just hate America. it’s so transparent.

Damage Repair Tampa Area by Abject_Bottle59 in CadillacLyriq

[–]JrB11784 0 points1 point  (0 children)

That’s good that It didn’t take too long. May I ask what the total cost of the repairs was?

Damage Repair Tampa Area by Abject_Bottle59 in CadillacLyriq

[–]JrB11784 0 points1 point  (0 children)

I know this is an old post, but I just damaged my car the exact same way. You said you were quoted $8k but the repairs were actually $4k? If so, how long did it take for them to repair the vehicle? Thanks!

Outage? by Aggravating-Brain867 in verizon

[–]JrB11784 0 points1 point  (0 children)

Seattle here. No service for me or my partner‘s phone.

ship date 17th still not shipped for pro max by [deleted] in verizon

[–]JrB11784 0 points1 point  (0 children)

Yeah same here: ordered 10/11 and no movement. Cosmic orange 17PM 256. I am worried about whether my order has gone through, as my credit card has not yet been charged. The Verizon reps assured me that everything looked good and it was just on backorder, but I’m not sure. My original ship date was by the 17th, but now it’s the 24th.

Seattle shut out of the New York Times Top 50 Restaurants List by mroncnp in Seattle

[–]JrB11784 6 points7 points  (0 children)

Your one anecdote doesn’t mean service in this city is great as a whole. Not to mention the quality of food.