I feel compelled to say that the high rise

[PCIntern]

went down exactly like that at a demolition site. Yes…I know. It’s ridiculous, right?

Absurd, actually. It’s just….I haven’t seen this happen before in America to my recollection. And yes, I work exactly next to a building which collapsed in Center City Philadelphia which destroyed a Lululemon store which was adjacent on Walnut Street….but it didn’t pancake, the upper floor wall and cornices gave way and crashed. The building was largely intact.

This was certainly weird…I hope they find what caused this and inspect other buildings so that it doesn’t happen again. I grieve for the victims and their families.

[LonePirate]

1. My money is on a sinkhole causing the collapse. Sinkholes are common in Florida.

[ornotna]

2. Not very common in South Florida though

Much more common in West Central Florida.

[teach1st]

3. Sinkholes require some rock underneath the ground

Florida barrier islands don't have a rock substrate.

https://blogs.scientificamerican.com/rosetta-stones/the-true-story-of-the-mar-a-lago-sinkhole/

[Croney]

6. A resident, now missing, called her husband and said

the building was shaking, and she'd seen out the window that there was a sinkhole where the pool used to be. Then the line went dead. Anecdotal, but still.

[ornotna]

13. From the pictures I've seen

The pool is still intact.

[csziggy]

22. Sinkholes tend to collapse when the ground water dries out

Which does not happen next to the ocean. The limestone of the underground caverns is dissolved by acidic water. When the limestone dries out, it becomes more brittle and is prone to collapsing.

Sinkholes tend to happen more inland and in places with a slightly higher ground level. Lowlands, swamps, and sea shores are not as likely to have sinkholes.

[Earth-shine]

4. Miami is one giant sink hole.

https://www.nzherald.co.nz/world/miami-building-collapse-high-rise-tower-was-sinking-for-decades-before-it-collapsed/2NBOXEN3IVC5P2CNU2JEYOOXRA/

[Baitball Blogger]

5. I'm guessing that there is going to be a demand for building inspector.

How long before someone figures out that we need more regulation in the construction business?

[sop]

11. The bribing of building inspectors in Miami-Dade County has been an ongoing scandal for decades.

Local Miami media cover these bribery cases constantly, but nothing seems to change. After Hurricane Andrew tore through South Miami, insurance inspectors found most of the collapsed structures didn't meet building codes. It turned out many builders had bribed inspectors to look the other way while they put up homes that wouldn't stand up to a gale force wind. Dozens of suits were filed by insurers to recover bilions of dollars paid out after the storm.

[Baitball Blogger]

14. It's going to get expensive for someone.

I think one of the biggest flaws in America is that we have to depend on private lawsuits to resolve flagrant issues that could have been resolved with proper public government scrutiny. Florida government is so corrupt, that it takes something this big to gather the public support needed to override the idiocy of the Libertarian style...and of course, rank corruption. In my book, the two go hand in hand.

[smirkymonkey]

7. When has a building in this country ever gone down like that, that wasn't acted upon by

an outside force? The last building I lived in (17 floors) used to scare the hell out of me. It was built in the 60's and faced the Charles River and Boston Harbor with very little to block those winds coming off the water. it constantly shook during high winds.

I was there during hurricane Sandy, the first year I moved back to Boston from NYC. I was absolutely terrified. Not only did the power go out for days, but I really thought the building was going to come down. I have never felt more vulnerable in my life.

I am so glad I moved out of there. I am now in a building that is a bit older and never shakes.

What a nightmare for those poor people in Florida. I just hope they didn't suffer very much. It's just horrific.

[NutmegYankee]

21. Harbour Cay Condominium, 1981 nt

[smirkymonkey]

23. Never heard about that one, although I was pretty young when it happened.

Another Florida building. Only 11 dead but still very tragic.

However this was quite different, it was brand new construction and they said that the concrete that was poured did not have time to dry before they added the additional layers, which was what they thought was responsible for the building collapse.

Some of the workers on the top floor actually rode the collapse all the way down and were unharmed.

Yesterday's collapse was of a 40 year old building, so very different conditions. I suppose we will be hearing a lot more about this in the coming days. Very sad for all involved.

[NutmegYankee]

24. They were built in the same year.

It’s possible similar mistakes were made in construction. The 1981 collapse was not caused by wet concrete, the steel reinforcement design was inadequate.

[smirkymonkey]

26. The article I read said it collapsed the day it was just about to be finished, not

exactly sure of the cause, but here is the Orlando Sentinel article. First, the quote from the paper:

"Construction was just finishing on the Harbour Cay Condominium building in Cocoa Beach when it suddenly collapsed on March 27, 1981. The accident killed 11 people and injured nearly two dozen."

https://www.orlandosentinel.com/news/florida/os-ne-cocoa--20210624-4mp5l2gjjvahfj2bdlx7vgceyq-story.html

Either way, they were both very tragic, but this one collapsed almost upon completion, whereas the other had been standing for about 40 years before its collapse.

[NutmegYankee]

27. That's a poorly done article. Investigation by the NBS and OSHA revealed design errors.

https://www.govinfo.gov/content/pkg/GOVPUB-C13-c3d64fd6d7663600a6e3a147919af0a1/pdf/GOVPUB-C13-c3d64fd6d7663600a6e3a147919af0a1.pdf

https://www.selicensure.org/what-were-doing/case-study/collapse-harbour-cay-condominium

It's possible for similar design errors to survive 40 years and then have corrosion or settling of the foundation finally serve as the proverbial straw that broke the camels back.

[smirkymonkey]

28. Wow, pretty comprehensive report. I just read the executive summary, but convincing

enough. I am not involved in construction or engineering, so any more detail would just confuse me.

Do you think this was just about developers cutting corners, or was it an honest mistake? Interesting that they were both in Florida.

This is pretty scary, but what really worries me in this country are bridges. I think it's just a matter of time before we have a major bridge collapse in this country.

Thanks for posting the reports!

[sop]

8. I'm not a structural engineer, but I did spend the night at a Holiday Inn Express...

I, too, hope other buildings in the area will be much more rigorously inspected in the future following this tragedy.

[DVRacer]

9. Is anyone besides me connecting the very large undersea

Detonation by the Navy just before more than a coincidence?

[Withywindle]

10. The building had been sinking since the 1990s

A geology professor's take on it: https://www.wfla.com/news/florida/ground-under-collapsed-florida-condo-had-been-shifting-since-1990s-geologist-says/

It was built on "reclaimed" wetland and it was not well maintained. There'd been a lot of complaints about leaks and cracks.

If the ground isn't stable, then...

[StarfishSaver]

12. I don't know anything about building engineering so far be from me to speculate

I'll wait for some official findings.

[uncle ray]

15. i see what you did there.

[Quixote1818]

16. It just takes one floor to break away for everything to pancake. nt

[tavernier]

17. They said several times on CNN

that a resident had told a family member the day before it happened that she hadn’t slep at all the previous night because of strange creaking noises from above. That sounds like it wasn’t an instantaneous thing.

[PCIntern]

18. Oh boy...

Frightening.

[Quixote1818]

19. A condemned building pancaked in Miami in 2018. WAS NOT a demolition

https://www.local10.com/news/2018/07/23/worker-hurt-when-building-set-for-demolition-collapses-in-miami-beach/

[NutmegYankee]

20. It fell in the direction of gravity.

The last portion topped over in the direction where the supports had been knocked/ripped out. Engineering-wise it acted as I expected.

[GulfCoast66]

25. I live in Florida and often stay in waterfront properties when on fishing trips.

Never big buildings like this. But 1-3 story houses. People underestimate the damage salt can do. Not so much to the concrete but to the rebar and steel girders that hold up the concrete. If you live if Ohio or even central Florida a small crack in the concrete is no big deal. But have salty air and spray going in there daily can rot out iron fast. I maintain a boat used in salt water. It is a constant battle.

When the metal rusts it expands. Pushing out and further weakening the concrete. And the iron loses its ability to flex. Add in some Settling of the building and you have a perfect storm.

Plus this was a condo building and that may turn out to be the largest problem. It can cost millions to repair this type of damage. Costing homeowners tens of thousands and they have to vote on it.

My prediction is that there were warnings. But the homeowners association did not want to spend the money to fix it.

I may be wrong. But I’ve seen these group owned buildings on the coast fall apart because the owners can afford the cost of the unit, but have no idea of what maintenance on an ocean front building costs.

[sop]

29. "But have no idea of what maintenance on an ocean front building costs."

Developers in South Florida have been putting up shoddy oceanfront buildings for decades. Typically corners are cut and the money is put into flashy design and luxurious amenities. And once all the units are sold, developers leave and the unit owners' association becomes responsible for all future repairs and maintenance.

Years later, after owners realize the incredibly high costs of maintaining the structural integrity of these buildings, they balk at the added monthly assessments and put off making repairs till it's too late. There are a lot of buildings in South Florida facing the same fate. This building collapse will create a huge ripple effect throughout South Florida.

[GoCubsGo]

31. Actually, it can affect concrete, as well, depending on the salts.

Alkali soils, especially those containing lots of sulfates, deteriorate concrete. They are a big problem out West, in particular, but also elsewhere. It does a real number on concrete foundations. I don't know what the situation is in that part of Florida, but the underlying geology in much of the state is limestone, which is alkaline. I wouldn't write off concrete damage, too.

From what I understand, these buildings are only inspected once every 40 years. That's nuts. So much can go bad in less time than that.

[Klaralven]

30. The building in downtown Philly was probably steel frame

Steel frame buildings don't tend to progressive failure like reinforced concrete buildings. Steel columns may buckle, but they won't break. The attachments between vertical columns and floor beams are able to bend, rather than shear off.

In a reinforced concrete building, when a lower column breaks, the column segment above it drops allowing the floor beams to drop. The drop of the floor beam ends twists the adjacent columns, causing them to break. The failure thus propagates from column to column.

[Sympthsical]

32. Once the supports go, it's only a matter of time

If you look at things like the Sampoong incident in South Korea or the Hotel New World collapse in Singapore, you'll see they have much in common. Once the pillars stop working in tandem with the flat slabs due to erosion, weakening, or lack of design, you'll see it can all go down very quickly. Usually there are warnings. In both cases, the warnings were ignored.

Right now, we have an engineer's report detailing that the Miami building had some of these problems.

It seems more and more we're looking at sea water erosion and a lack of timely maintenance of the issue. And if that engineer's report is true, someone or someones are getting the daylights sued out of them. And after something like this, there need to be some criminal charges.