Miami Beach, Champlain Towers South apartment building collapse, Part 07 90

[Seppe]

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[gonefishing2]

@Demented, The balcony slab in the picture (number 9 marking) sure looks like it could come from Unit 511. The 511 living area tile/marble floor is a lot higher than the tile floor on the balcony, and the slab #9 shows cracking under the exterior wall/sliding door.

And I too see the signs of sagging slab at sliding door. At top and bottom.

And back to double front door, I now think the right side wall is no longer parallel to the left side, thus racked and perhaps sloping floor too.

Right door may have been cut off at bottom, so it would not drag due to racking of jamb wall. Look at tapered gap between active panels.

The marble floor cracks and slopes do not look right either, and look like they are sloping towards sliding door/outside wall....

I don't remember how long ago was the renovation of 511, but they sure added lots of weight to that floor slab!

Could 511 be first building slab failure? Definitely it is on the list, IMO.

Edit: Was 511 renovation after 2018 Morabito report? How much individual unit renovation was done between 2018 and 2020 when Morabito got back involved, and sounded a stronger alert this time.

Edit2: The construction next door causing shaking of building was after 2018 Morabito report, and finishing up probably around the 2020 timeframe. So how much of a contributing factor was the pile driving, especially sheet piles within 10 feet of building...

 

[tmwaits1]

Well this seems like a very reasonable comment to make, but the truth is that there was nothing in the 2018 report that would indicate that the building was “terminally weakened” and going to collapse 3 years later. None of the issues that were noted were anywhere near the level of deterioration that would cause any structural engineer to say the building was unsafe for occupancy. People need to understand that structural engineering isn’t just about creating a structure that will carry the loads, but is also about designing such that if failure occurs, it happens in a ductile, progressing manner that reduces or eliminates loss of life. The biggest mystery to solve in all this is why there were not more warning signs.

 

[gonefishing2]

Unit 511 sold on 5/5/21. So was renovation done specifically to hide the defects in the floor so unit could be flipped at a nice price?

All I found on Surfside Permits was Unit 511 got a new Rheem AC in 2019, with hurricane rated tie down straps.....

Unit 711 just got a Permit before collapse for new tiles..... Hmmmm.....

Unit 711 just got 6 new windows and storm rated sliding door in 2020.....

Boy we sure have a trend going here, and I know Demented already knows all this.......

Unit 211 and 311 both getting or got new AC's

unit 211 gets $76K renovation in 2015 including new floor, new kitchen cabinets, new plumbing fixtures, etc....

 

[Spartan5]

Thermopile… can you find any pics of their home theater setups? Maybe they had some big speakers and subwoofers. That’s more load, plus more vibrations. Perhaps someone was using them to try to set up some sort of harmonic to bring the building down? Hmmmmmm… ……… … —- …

 

[gonefishing2]

@Spartan5, that was a low blow!

 

[Demented]

@thermopile
Unpermitted bathroom renovations were done recently (Feb/March 2021ish), but it appears that the marble floor has been in that unit for some considerable time. There's a renovation on record with no details in 1981, but I'm still having no luck finding anything in regards to when work was done. The kitchen was possibly done some time in 2003, which would be my guess for when the marble flooring would have been installed. I'm sure internal emails will show if there were any noise complaints related to construction inside this unit.



Precision guess work based on information provided by those of questionable knowledge

 

[JAKLED]

[
I am open to the idea of roof-first collapse, it is a valid possibility but still have seen no evidence for it. The security video that shows the collapse does not show the penthouse collapsed, but the whole building collapsing. At least without the first frames (which indeed are missing), the video is not definitive and can be (and is) interpreted both ways. The roof-first theory also requires a longer sequence of coincidental events. The garage collapse theory only requires chronic fatigue of garage level columns, and given the evidence of water encroachment into the basement, remains the simplest and most likely theory./quote]

Microwizard, I will have to challenge your quote for contrast but I do so respectfully and with an open mind as well. I am going to make a few points on here then let it be and let time tell what we all have spent hours trying to conclude.

Before I stumbled onto this thread, I had my own preliminary theories on the “core” trigger point due to a trajectory of poor decisions and almost laziness to act on extensively documented structural deterioration, avoiding the intentional act to ensure that this building was even safe for occupants to live in. And I still feel firm in knowing that the “core” priority of immediate construction needed to actually be focused on the “core” of the building itself. The foundation, the structures where, at its core, was screaming through years of water damage, evidence, and recent conclusion that the lower pool area/parking deck concrete, reshoring, and reinforcement MUST be first and foremost focused on and invested in NOW. And the simple fact that during the board meeting focus was actually being honed in on the ROOF first, which for reiteration of “simple”, also heeded the lack of guidance that with all the evidence of concrete deterioration and warnings of structural integrity, guidance and enforcement of ensuring the fundamental strength and integrity of the foundation and “core” MUST be completed FIRST before any consideration above thereof.

And making the executive decision to work on the roof as a top priority was the initiating event that continued feeding the history of “putting lipstick on a pig” except more like “putting more Jenga blocks on top.”

I digress.

I will make my 4 points now.

1) We only tangibly have few “witness” accounts from those who lived deeper in Champlain South, and unfortunately, we will never be able to hear more about the experiences of those who lived on higher floors. But the few accounts given seemed that the residents were very stoic and matter of fact - Not given in sheer panic due to the aftermath of a crisis situation, but more so given in firm and clear communication about the integrity of the building as a result of the recent roof work ensuing with a common concern about the present and future of the building in what seemed to be a “duty to warn”.
-” Fiorella Terenzi who lived in Champlain Towers East and who had a clear view to CTS, was quoted in an NYT article, “Ms. Terenzi said she had seen heavy equipment on the roof of the south tower for the past two weeks.”
- Pablo Rodriguez, said his mother called him to report "creaking noises" she heard a day before the building collapsed.
- Douglas Berdeaux gave an account of how Sabino was very concerned about the roof construction and “said it was vibrating her unit”. “She even went up to talk to the construction manager and told them whatever they were doing was making her rooms vibrate. She said she was worried that the ceiling was going to collapse on top of her bed. She also said she heard water around the elevator. A manager went up to her unit with her and looked around, and told her they’re doing some work, but everything was okay.”
-There was also significant water damage on the roof, right above the failed column in the garage, and Sabino clearly heard water around the elevator to the extent of where she knew it was substantial enough to report, and from there not being corrected or alerted for it doesn’t seem like it was a “normal” event to be occurring at the time.
Roof results of significant water damage documented:

2) Crashing was reported initially as being from above - if individuals attested for crashing coming from above, wall cracking coming from above, it was probably coming from above. Now talk about simple conclusions. (Quote: In a video interview her 15-year-old daughter Chani said, “I went to take a shower and I came out of the shower dried myself and I was about to get dressed and hear like a big boom and I was like oh no something’s not right and I just ran out of the bathroom and I checked and I thought the whole ceiling was like collapsing.” )
The wall appears to have been torn at an angle of destruction, given the triangle hole, and restating from a post a few weeks back, a cantilever and/or balcony area could have actually torn away from that spot, given a roof anchor was just test loaded :

Ironically, a roof anchor crashed into the still-standing adjacent 8th-floor hallway wall which indicates that the "roofing event" dislodged from above could have stayed almost flush to collapsing straight down into that nook along the wall - hitting the compromised pool deck - but again, the initial boom event was probably not watched due to the time of day. And unfortunately, those who may have seen the roof event and have the answers were not able to make it out in time.

3) The building collapsed the day after the roof anchor permit was given to test load. The building had structural issues deep within its core of stability, and the many years of deterioration and what seems like an extensive and progressive weight being added to each floor (heavier cars, marble here, marble there (see link to the penthouse photos) wood, stainless steel appliances with grandiose furniture, heavier HVAC units and recent work) which over time due to the increase in occupants’ “heavier lifestyle” paired with the systemic digression of structural integrity, the building finally gave in and the roof work and load testing was the straw that finally broke the building’s back. Simple facts.

4) Now for my conclusion, I believe the parking deck failure event and roof failure event HAPPENED AT THE SAME TIME. Instead of either/or, its a contiguous and.

From the initial crashing sound as a warning of what was to come, it was only a short matter of time this almost 40-year old building could "hold on" and displace weight without adequate rebar steel reinforcement & sheer wall support.

And im out. Thanks for reading if you made it this far!

 

[Demented]

Unit 511 sold on 5/5/21. So was renovation done specifically to hide the defects in the floor so unit could be flipped at a nice price?

All I found on Surfside Permits was Unit 511 got a new Rheem AC in 2019, with hurricane rated tie down straps.....

Unit 711 just got a Permit before collapse for new tiles..... Hmmmm.....

Unit 711 just got 6 new windows and storm rated sliding door in 2020.....

Boy we sure have a trend going here, and I know Demented already knows all this.......

Unit 211 and 311 both getting or got new AC's

unit 211 gets $76K renovation in 2015 including new floor, new kitchen cabinets, new plumbing fixtures, etc....

It's not just up and down this building. It's up and down this coastline.

We don't engineer things, we over engineer things. And by over engineer, we go up in size 2x on everything to make doubly sure that it's strong enough. More gravity means more gooder.
Why of why did I leave aerospace for the south Florida structural scene...

As far as your speculation on new renovations hiding damage to increase the price to flip it, possibly. That is the norm these days. Home Depot will do everything for you, from permit to install. No inspections required because it's all assumed to be engineered.



Precision guess work based on information provided by those of questionable knowledge

 

[spsalso]

To be added to all new condo sales contracts:

"If you remodel, you cannot add any weight, as it will make the building fall down."

Might want to add in something about heavy furniture, too. And maybe no overweight people.


spsalso

 

[Demented]

@Spalso

Last year I viewed two condo units where there were restrictions on furniture weight.


Precision guess work based on information provided by those of questionable knowledge

 

[AusG]

You raise an excellent point. I was mainly trying to steer away from roof vs nonroof wrangling. The issue of "once collapsing, why so catastrophically?" is a more useful line of inquiry for future public safety. A question though re Morabito in 2018. I read his report, i.e. significant but reversible problems now but with exponential deterioration predictable, as being as close to predicting an impending terminal state as could be expected without seeing broken structural elements in plain view. Would you see it that way?

 

[CE3527]

So the roof anchor permit is dated June 23, 2021 and the condo collapsed at approximately 1:20am +/- on June 24, 2021, less than 24 hours after the permit was issued. My experience with permits is generally the contractor doesn't schedule the work until they have the permit in hand, because sometimes there are unknowns on when you'll actually get it once you apply. Is there evidence that the contractor mobilized to the project and installed these anchors before the collapse?

 

[Auri]

So many seem to conflate temporal proximity with causation. Anchor load testing is not column load. It's tying two roof points with a chain hoist, thereby compressing roof slab laterally. If it doesn't crack then, it's really hard to believe it would crack with no load that very night. Anchors are like 45 lbs a piece. The real stress of re-roofing comes from the size of crew doing it. All that vibrating equipment to remove old asphalt, all that old/new material being wheeled around for crane access can certainly cause structural damage if not managed well - that work reportedly happened late May into June.

This one's not structurally important but gets on my nerves:

Ironically, a roof anchor crashed into the still-standing adjacent 8th-floor hallway wall

 

[AutisticBez]

I guess at this point you might consider it hard to sell 40 year old condo's?

Perhaps there should be some form of retirement assistance for old buildings like this? Get rid of them.

 

[AusG]

Can someone please explain how those roof anchors were intended to be used? You could not work on the exterior with a safety line or worse an abseiling line tied off at the roof and going over a rough parapet of unknown competence and at those angles. It seems unthinkable.

 

[dik]

The anchors are for fall arrest and have to be strong enough to resist a load of 5000 lbs (22 kN).

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[jimstructures]

AusG

Based on 30 years in Metal Building Structures, where we install those type of personnel tie-off anchors, they are used to work near the edge of the roof, say approximately 10' wide zone all around the roof. Not for suspension work over the edge of roof. One Anchor One person, maybe two persons tied off. Simply fall protection tie-off.


Jim

 

[AusG]

Sure, I get how the bolts work. it's what happens to the line you tie to it I don't get. The lack of a clear path for the rope or cable or whatever.

Edited: ah OK, Jimstructures, thanks that's clear. They had previously been discussed in terms of high access work over the side, cages and the like.

 

[JAKLED]

??

 

[hochhaul]

https://res.cloudinary.com/engineering-com/image/upload/v1626658624/tips/E6Ipf41XoAo9FwK_gfimoy.jpg

"It appears this would have been by the lobby entrance area, on top of the deck? 2 ton tar tank (~800-900psf if left full for next morning as is typical of the area). This wouldn't have been parked under ground in the garage would it have been?"

The position of that Camry appears to be out of place. Possibly due to the rush to remove debris from the collapse site? In the parking garage video from last year, it was parked here: