Would the WTC Twin Towers have collapsed from fire alone, without plane impact?

[benthamitemetric]

Exactly, and now take it one step further. It's the kinetic energy that is used to destroy the floor below. Energy is neither created or destroyed, so the energy to destroy the floor is subtracted from that kinetic energy, and the equation for kinetic energy is 1/2 mv^2. If the mass isn't decreasing, what has to decrease for the kinetic energy to destroy the floor below?

Look at NIST's calculation again. The weight of 6 floors suddenly applied to a single floor will destroy that single floor without the need for any additional energy. So the impact with the first floor could take all of the energy out of the falling mass (though obviously it does not and NIST's equations are so conservative because they do not even account for the massive amount of energy from the momentum of the fall) and that mass would still again have enough energy to destroy the next floor if suddenly applied (and, again, this is without taking into account the floor's worth of acceleration before that second floor is impacted). Do you get it now? This is why NIST's calculation should show without a doubt to anyone who understands it that total collapse was inevitable. It is trivial, frankly.

18. Was there enough gravitational energy present in the WTC towers to cause the collapse of the intact floors below the impact floors? Why weren't the collapses of WTC 1 and WTC 2 arrested by the intact structure below the floors where columns first began to buckle?
Yes, there was more than enough gravitational load to cause the collapse of the floors below the level of collapse initiation in both WTC towers. The vertical capacity of the connections supporting an intact floor below the level of collapse was adequate to carry the load of 11 additional floors if the load was applied gradually and 6 additional floors if the load was applied suddenly (as was the case). Since the number of floors above the approximate floor of collapse initiation exceeded six in each WTC tower (12 floors in WTC 1 and 29 floors in WTC 2), the floors below the level of collapse initiation were unable to resist the suddenly applied gravitational load from the upper floors of the buildings.

Consider a typical floor immediately below the level of collapse initiation and conservatively assume that the floor is still supported on all columns (i.e., the columns below the intact floor did not buckle or peel off due to the failure of the columns above). Consider further the truss seat connections between the primary floor trusses and the exterior wall columns or core columns. The individual connection capacities ranged from 94,000 pounds to 395,000 pounds, with a total vertical load capacity for the connections on a typical floor of 29,000,000 pounds (see Section 5.2.4 of NIST NCSTAR 1-6C). The total floor area outside the core was approximately 31,000 square feet, and the average load on a floor under service conditions on Sept. 11, 2001, was 80 pounds per square foot. Thus, the total vertical load on a floor outside the core can be estimated by multiplying the floor area (31,000 square feet) by the gravitational load (80 pounds per square foot), which yields 2,500,000 pounds (this is a conservative load estimate since it ignores the weight contribution of the heavier mechanical floors at the top of each WTC tower). By dividing the total vertical connection capacity (29,000,000 pounds) of a floor by the total vertical load applied to the connections (2,500,000 pounds), the number of floors that can be supported by an intact floor is calculated to be a total of 12 floors or 11 additional floors.

This simplified and conservative analysis indicates that the floor connections could have carried only a maximum of about 11 additional floors if the load from these floors were applied statically. Even this number is (conservatively) high, since the load from above the collapsing floor is being applied suddenly. Since the dynamic amplification factor for a suddenly applied load is 2, an intact floor below the level of collapse initiation could not have supported more than six floors. Since the number of floors above the level where the collapse initiated exceeded six for both towers (12 for WTC 1 and 29 for WTC 2), neither tower could have arrested the progression of collapse once collapse initiated. In reality, the highest intact floor was about three (WTC 2) to six (WTC 1) floors below the level of collapse initiation. Thus, more than the 12 to 29 floors reported above actually loaded the intact floor suddenly.

 

[Henkka]

Look at NIST's calculation again. The weight of 6 floors suddenly applied to a single floor will destroy that single floor without the need for any additional energy. So the impact with the first floor could take all of the energy out of the falling mass (though obviously it does not and NIST's equations are so conservative because they do not even account for the massive amount of energy from the momentum of the fall) and that mass would still again have enough energy to destroy the next floor if suddenly applied (and, again, this is without taking into account the floor's worth of acceleration before that second floor is impacted). Do you get it now? This is why NIST's calculation should show without a doubt to anyone who understands it that total collapse was inevitable. It is trivial, frankly.

Wrong answer. At the moment of impact, the kinetic energy of the falling mass was E = 1/2 * mass * velocity^2. If the mass stays the same, what has to decrease in order for that mass to break apart anything below it?

 

[Gamolon]

My best theory is that the collapses could have been slowed and eventually arrested because much of the load would not just impact the floor connections but the columns, especially in the core.

To benthamitemetric's point above, how would the columns catch all this and stop it?

Let's use the largest core column size which is 22" x 54". Multiply that area by 47 columns and we get 387.75 square feet of column area. The towers were 208' x 208'. So the area of the lowest floor of the upper block would be 43,264 square feet.

All 47 core columns (using the column dimensions above) only make up .9% of the total area of the lowest floor of the descending upper block that would impact them.

 

[Mendel]

Destruction requires energy. Where does the energy come from that destroys this floor?

potential energy of the weight "resting" on the floor

dude, have you never seen anything break because it was loaded too heavily?

if you've ever sliced a tomato with a well-honed knife, you'll know you don't need much ENERGY to break something

what matters is FORCE

 

[benthamitemetric]

Wrong answer. At the moment of impact, the kinetic energy of the falling mass was E = 1/2 * mass * velocity^2. If the mass stays the same, what has to decrease in order for that mass to break apart anything below it?

Breaking the floor requires energy. But the falling mass in this case can expend that energy still always have sufficient energy to proceed through the subsequent floor. No new energy required; it all comes from a conversion of the potential energy within the building at the start of the collapse. This, again, is without taking into account that (1) the accelerations of the mass between floor impacts is adding energy (beyond the de minimis amount needed to simply suddenly apply the mass to the next floor (see again NIST's point re the dynamic amplification factor)), and (2) the mass that is falling is actually increasing with each broken floor. NIST shows very clearly that there is more than enough energy in the system to continue breaking floors all the way down.

 

[Thomas B]

How could the columns catch the bulk of the falling mass? Please describe in detail how you think the force of the falling debris would be transferred to the columns in way that is not accounted for in NIST's very conservative calculation of the strength of the floors (which strength was based on the floors' connection to the columns).

I suppose the floor pans would hit the tops of the columns. That would take the load off roughly half the connections on the floor below (and transfer them to the connections in ceiling above). Beyond that, it's not very clear to me what would happen, but I've heard ROOSD proponents invoke "chaotic" effects and my inclination is to do the same. Like I say, I imagine the rigid steel frames of the top and bottom sections getting somehow "tangled up" in each other.

The frames were very strong laterally and they were completely destroyed. So some of that downward motions must have gone into overcoming the lateral (wind-resisting) strength of the building. After all, when the building was operating normally, all lateral forces were ultimately converted into vertical forces and transfered into the the ground. That's how buildings work.

 

[benthamitemetric]

I suppose the floor pans would hit the tops of the columns. That would take the load off roughly half the connections on the floor below (and transfer them to the connections in ceiling above). Beyond that, it's not very clear to me what would happen, but I've heard ROOSD proponents invoke "chaotic" effects and my inclination is to do the same. Like I say, I imagine the rigid steel frames of the top and bottom sections getting somehow "tangled up" in each other.

The frames were very strong laterally and they were completely destroyed. So some of that downward motions must have gone into overcoming the lateral (wind-resisting) strength of the building. After all, when the building was operating normally, all lateral forces were ultimately converted into vertical forces and transfered into the the ground. That's how buildings work.

How would the floor pans hit the tops of the columns if the floor collapse is proceeding ahead of the column collapse?

 

[Mendel]

The frames were very strong laterally and they were completely destroyed.

Yes. They were not "attacked" laterally, but vertically.

Structural strength is often directional.

 

[Thomas B]

How would the floor pans hit the tops of the columns if the floor collapse is proceeding ahead of the column collapse?

I'm imagining it sort of like Mick's bookcase model. On the left side, the floor connections are being broken downwards, but on the right hand side they're being broken upwards, one floor up.

 

[Henkka]

Breaking the floor requires energy. But the mass still has sufficient energy to always proceed through the subsequent floor. No new energy required; it all comes from a conversion of the potential energy within the building at the start of the collapse. This, again, is without taking into account that (1) the accelerations of the mass between floor impacts is adding energy (beyond the de minimis amount needed to simply suddenly apply the mass to the next floor (see again NIST's point re the dynamic amplification factor)), and (2) the mass that is falling is actually increasing with each broken floor. NIST shows very clearly that there is more than enough energy in the system to continue breaking floors all the way down.

Again...

E = 1/2 mass * VELOCITY^2

If that kinetic energy is used to break the floor, the kinetic energy has to be less at then end of that process. Something in that equation has to therefore decrease, does it not? And it's not the mass, so...

 

[Thomas B]

Yes. They were not "attacked" laterally, but vertically.

Well, on the ROOSD theory, the columns weren't attacked vertically or laterally. Only the column-to-floor connections were broken. The columns then collapsed under their own weight for lack of lateral bracing.

Structural strength is often directional.

This is the sticking point. My sense of structures like this is that they're integrated to distribute loads in all directions as needed. The lateral loads are translated into vertical loads which means that the columns have to account for more than forces operating originally only in the direction of gravity. They must be strong enough to support wind in all directions too (including up and down, I'm told).

 

[benthamitemetric]

I'm imagining it sort of like Mick's bookcase model. On the left side, the floor connections are being broken downwards, but on the right hand side they're being broken upwards, one floor up.

Doesn't seem realistic to me in the context of this collapse, but, even if it were, then its still not a question of the strength of the column as much as it is a question of the strength of the floor pan given the wave of debris pushing it down. In any case, hard to see how you take this weird edge case scenario and imagine it is meaningfully substracting from the force of the falling debris.

Again...

E = 1/2 mass * VELOCITY^2

If that kinetic energy is used to break the floor, the kinetic energy has to be less at then end of that process. Something in that equation has to therefore decrease, does it not? And it's not the mass, so...

Do you think it is possible to overload a structure by slowly placing weight upon it in increments? If so, how do you think that works?

 

[Thomas B]

Doesn't seem realistic to me in the context of this collapse, but, even if it were, then its still not a question of the strength of the column as much as it is a question of the strength of the floor pan given the wave of debris pushing it down.

Like I say, it requires us to think of both the upper and lower sections and tightly integrated structures that always distribute whatever loads impinge on any part to the rest (rather than always directly and immediately breaking the weakest link).

In any case, hard to see how you take this weird edge case scenario and imagine it is meaningfully substracting from the force of the falling debris.

The other extreme case is imagining the whole upper section suddenly (magically) turning into water or sand with the same total mass. That is, what happens if it really just is "falling debris" and not a structural system. I tend to agree with @Henkka that, though obviously a disaster in its own right, it would not have nearly the same catastrophic consequences for the lower section.

So we're stuck between these clear "edge cases" and the reality that truthers think is impossible and debunkers think is obvious.

 

[benthamitemetric]

Like I say, it requires us to think of both the upper and lower sections and tightly integrated structures that always distribute whatever loads impinge on any part to the rest (rather than always directly and immediately breaking the weakest link).

The other extreme case is imagining the whole upper section suddenly (magically) turning into water or sand with the same total mass. That is, what happens if it really just is "falling debris" and not a structural system. I tend to agree with @Henkka that, though obviously a disaster in its own right, it would not have nearly the same catastrophic consequences for the lower section.

So we're stuck between these clear "edge cases" and the reality that truthers think is impossible and debunkers think is obvious.

*We're* not really stuck so much as truthers are stuck because there is no fact-based argument that any of the floors in either tower could withstand the load of the portion of such tower above its initial point of failure. So they are stuck with incredulity and magical, nonfasfiable throwaway arguments such as that the columns being bypassed by the collapsing floors could somehow, someway, stop those floors after their connections to those floors were severed.

By the way, since you like helping truthers so much, do you see the error in Henkaa's argument? You don't seem to be making the same error, so perhaps you could try to explain it to him.

 

[Henkka]

Do you think it is possible to overload a structure by slowly placing weight upon it in increments? If so, how do you think that works?

Since it seems like you don't want to, I can answer my own question... It would be the velocity that would have to decrease in order for that kinetic energy to be used to break apart anything. But it didn't.

As for this new question, I don't see how it relates to the WTC collapses, since obviously the weight at the top was not being slowly increased in increments. I'm guessing you want to turn this around into saying that weakening the structure while the weight stays the same can have the same effect as increasing the weight, ie causing a collapse. I would agree with that, but only if the entire structure was being weakened. But where was it being weakened? Only at the impact zone, where there were several floors on fire. Under that, you had 47 massive, stone cold and undamaged vertical columns in the core putting up constant resistance, and they're not going anywhere. Because of this reason, I also don't see how there could be "accelerations of the mass between floor impacts" like you proposed earlier.

 

[benthamitemetric]

Since it seems like you don't want to, I can answer my own question... It would be the velocity that would have to decrease in order for that kinetic energy to be used to break apart anything. But it didn't.

As for this new question, I don't see how it relates to the WTC collapses, since obviously the weight at the top was not being slowly increased in increments. I'm guessing you want to turn this around into saying that weakening the structure while the weight stays the same can have the same effect as increasing the weight, ie causing a collapse. I would agree with that, but only if the entire structure was being weakened. But where was it being weakened? Only at the impact zone, where there were several floors on fire. Under that, you had 47 massive, stone cold and undamaged vertical columns in the core putting up constant resistance, and they're not going anywhere. Because of this reason, I also don't see how there could be "accelerations of the mass between floor impacts" like you proposed earlier.

If you took the mass of the top block and slowly placed it on the next floor down in increments, it would collapse that floor, no?

 

[Thomas B]

do you see the error in Henkaa's argument? You don't seem to be making the same error, so perhaps you could try to explain it to him.

I'm not sure I have much to contribute there. @Henkka's reasoning seems mostly sound to me.

If we imagine compressing the mass of the upper section into a rigid, solid block (like a brick, but denser) with a footprint slightly larger than the towers) and dropping it from about 12 feet onto the structure below (so that it impacts the tops of the columns, not the floor connections), it's hard to imagine it crushing its way all the way to the ground at 2/3 g.

If, at the other extreme, we imagine that same mass in loose sand (so that it will mostly press down on the surface of the floor pans), it's also hard to imagine it crushing the whole building to the ground before it has dissipated off the edge of the building or down through the core's shafts.

Somewhere in between is the "falling debris" of the ROOSD model, which is supposed to do the job.

I have to say, I like Henkka's idea of getting you to split the brick first into four pieces and then on and on til you get to a pile of sand. Help me understand the exact degree of "structure" that the towers really had, to take us from the extreme cases (solid, fluid) that seem obviously to rule out total destruction to the real world scenario you think is so obvious.

 

[benthamitemetric]

I'm not sure I have much to contribute there. @Henkka's reasoning seems mostly sound to me.

If we imagine compressing the mass of the upper section into a rigid, solid block (like a brick, but denser) with a footprint slightly larger than the towers) and dropping it from about 12 feet onto the structure below (so that it impacts the tops of the columns, not the floor connections), it's hard to imagine it crushing its way all the way to the ground at 2/3 g.

If, at the other extreme, we imagine that same mass in loose sand (so that it will mostly press down on the surface of the floor pans), it's also hard to imagine it crushing the whole building to the ground before it has dissipated off the edge of the building or down through the core's shafts.

Somewhere in between is the "falling debris" of the ROOSD model, which is supposed to do the job.

I have to say, I like Henkka's idea of getting you to split the brick first into four pieces and then on and on til you get to a bile of sand. Help me understand the exact degree of "structure" that the towers really had, to take us from the extreme cases (solid, fluid) that seem obviously to rule out total destruction to the real world scenario you think is so obvious.

Ok, then I'll just proceed with explaining it to Henkaa and hope that you eventually get it too.

 

[deirdre]

Since it seems like you don't want to, I can answer my own question... It would be the velocity that would have to decrease in order for that kinetic energy to be used to break apart anything. But it didn't.

just for the record ..he did answer you. twice. even i understood his answer and half this engineering stuff usually goes over my head.

 

[deirdre]

I have to say, I like Henkka's idea of getting you to split the brick first into four pieces and then on and on til you get to a pile of sand

when they talk about "the mass" i think it IS already a lot of "sand" (broken drywall, concrete floors) and the actual bricks/concrete have already been naturally split in 4.

at least that's how ive always pictured the "mass" since all that "sand" immediately began blowing out the windows. alot of "sand"

 

[Gamolon]

If we imagine compressing the mass of the upper section into a rigid, solid block (like a brick, but denser) with a footprint slightly larger than the towers) and dropping it from about 12 feet onto the structure below (so that it impacts the tops of the columns, not the floor connections), it's hard to imagine it crushing its way all the way to the ground at 2/3 g.

If, at the other extreme, we imagine that same mass in loose sand (so that it will mostly press down on the surface of the floor pans), it's also hard to imagine it crushing the whole building to the ground before it has dissipated off the edge of the building or down through the core's shafts.

Somewhere in between is the "falling debris" of the ROOSD model, which is supposed to do the job.

I have to say, I like Henkka's idea of getting you to split the brick first into four pieces and then on and on til you get to a pile of sand. Help me understand the exact degree of "structure" that the towers really had, to take us from the extreme cases (solid, fluid) that seem obviously to rule out total destruction to the real world scenario you think is so obvious.

The upper block didn't crush the lower block like a foot crushing an aluminum can. The upper block, which turned into a disconnected mass of falling debris, sheared connections on it's way down. Based on that, what can we tell about the structure that's left in the red oval?

There are no floors attached to the remaining core any more. How do you think that happened? Explosives were used to remove the floors connections? Or does it make more sense that the mass of debris impacted the floors and stripped/sheared them from the core columns?

 

[Thomas B]

when they talk about "the mass" i think it IS already a lot of "sand" (broken drywall, concrete floors) and the actual bricks/concrete have already been naturally split in 4.

at least that's how ive always pictured the "mass" since all that "sand" immediately began blowing out the windows. alot of "sand"

But do you agree that, if it really had turned into a pile of sand, it wouldn't have been able to destroy the building?

 

[deirdre]

But do you agree that, if it really had turned into a pile of sand, it wouldn't have been able to destroy the building?

no. sand is heavy. (have you ever filled a sandbox? it's brutal)
drywall dust is heavy ( i know this personally from vacuuming it up after sanding large rooms),
concrete dust is heavy.

do you agree that a column top could not stop a pile of sand? ( i'm saying you might want to drop the sand analogy)

 

[Thomas B]

The upper block didn't crush the lower block like a foot crushing an aluminum can. The upper block, which turned into a disconnected mass of falling debris, sheared connections on it's way down.

That's why I'm proposing the two extremes. It wasn't like a solid object dropped on the structure and it wasn't like a load of sand dropped on the structure. (Do you agree that neither seems capable of totally destroying a WTC tower?)

There are no floors attached to the remaining core any more. How do you think that happened? Explosives were used to remove the floors connections? Or does it make more sense that the mass of debris impacted the floors and stripped/sheared them from the core columns?

To me, the "mass of falling" debris has only a marginally better chance of causing this state of affairs than the extreme cases. In fact, I'm not sure I can explain why I think it's even a little more plausible. That's just a feeling. It would be indeed be much easier to understand if it had been done with explosives.

I assume you'd also understand an explanation that just told you where the explosives had been planted and when they had been detonated.

 

[Henkka]

If you took the mass of the top block and slowly placed it on the next floor down in increments, it would collapse that floor, no?

What do you mean by the "floor", here? The layer of concrete supported by the trusses? The building was already holding up the mass of the top block, so I don't quite understand what you're asking here.

just for the record ..he did answer you. twice. even i understood his answer and half this engineering stuff usually goes over my head.

Not really... He said the kinetic energy of the top block would destroy the floor below. But in order to do that, the kinetic energy must decrease, and its equation is E = 1/2 * mass * velocity^2. Since the mass is obviously not decreasing, instead the velocity must decrease. Now, the unsaid thing in this discussion is that we both know the velocity of the top block of WTC 1 did not decrease, it accelerated. So you have to wonder, how did that happen?

You can think about it this way... When you jump into a swimming pool, your body displaces water, right? You push it out of the way as you become submerged. And pushing water requires energy. The energy comes from the kinetic energy you built up as you fell. This makes it so that you slow down, instead of continuing to accelerate to the bottom of the pool and breaking all your bones.

 

[deirdre]

If we imagine compressing the mass of the upper section into a rigid, solid block (like a brick, but denser) with a footprint slightly larger than the towers) and dropping it from about 12 feet onto the structure below (so that it impacts the tops of the columns, not the floor connections), it's hard to imagine it crushing its way all the way to the ground at 2/3 g.

ps. you need to stop imagining this. that would be hard to imagine, that is Gage's cardboard box theory. but that is not what happened.

 

[Thomas B]

do you agree that a column top could not stop a pile of sand? ( i'm saying you might want to drop the sand analogy)

I'm saying a pile of sand could not collapse a column because the sand would pour off to the sides and through the shafts of the cores. The sand would reach the ground long before the building had been totally destroyed.

 

[Thomas B]

ps. you need to stop imagining this. that would be hard to imagine, that is Gage's cardboard box theory. but that is not what happened.

As long as we agree that the collapse would be arrested, we're on the same page.

 

[deirdre]

What do you mean by the "floor", here? The layer of concrete supported by the trusses?

yes he is saying the floor we walk on.

 

[deirdre]

I'm saying a pile of sand could not collapse a column because the sand would pour off to the sides and through the shafts of the cores. The sand would reach the ground long before the building had been totally destroyed.

but alot of it wouldnt pour down the core (or out into the air surrounding the building). most of it would settle on the floor (we walk on).

As long as we agree that the collapse would be arrested, we're on the same page.

i imagine it would be arrested. but since that didnt happen, no engineers i know of did the math for that scenario.
as far as i know everyone agrees if you drop a box on other cardboard boxes, the other boxes dont completely collapse.

 

[deirdre]

but alot of it wouldnt pour down the core (or out into the air surrounding the building). most of it would settle on the floor (we walk on).

actually @Thomas B , how would the sand get into the core? i mean other then a few open small doorways the core is a concrete chimney.

 

[benthamitemetric]

What do you mean by the "floor", here? The layer of concrete supported by the trusses? The building was already holding up the mass of the top block, so I don't quite understand what you're asking here.

I mean an actual floor system as described by NIST in the calculation we've been talking about for three days. What would happen if you slowly loaded the mass of one of the upper blocks onto an actual single floor system in either tower?

 

[deirdre]

But in order to do that, the kinetic energy must decrease,

i know that's what he said.

Now, the unsaid thing in this discussion is that we both know the velocity of the top block of WTC 1 did not decrease, it accelerated. So you have to wonder, how did that happen?

he explained that.

You can think about it this way... When you jump into a swimming pool, your body displaces water, right? You push it out of the way as you become submerged. And pushing water requires energy. The energy comes from the kinetic energy you built up as you fell. This makes it so that you slow down, instead of continuing to accelerate to the bottom of the pool and breaking all your bones.

i like that analogy. it might be helpful.
in my laymen language (im not an engineer), in your scenario yes the water decreases my speed upon impact but i "broke" the water. the top of the water is the floor (i walk on) and i broke it.

in the Twin Tower scenario that floor i just broke is traveling with me increasing my weight. each inch of water is a twin tower floor, and as i break through each inch of water, i carry that water weight i just broke down with me to the next inch.

 

[deirdre]

I mean an actual floor system as described by NIST in the calculation we've been talking about for three days. What would happen if you slowly loaded the mass of one of the upper blocks onto an actual single floor system in either tower?

even i dont know what you mean here. are you saying henkkas description is incorrect?
"The layer of concrete supported by the trusses?"

 

[benthamitemetric]

even i dont know what you mean here. are you saying henkkas description is incorrect?
"The layer of concrete supported by the trusses?"

It's not just the concrete held up by the trusses, it's the trusses and and joists as well. All of the things that compromised one of the floors of the building. I think it's pretty clear what NIST is talking about when they talk about an intact floor of the building. That's what I'm talking about.

 

[deirdre]

It's not just the concrete held up by the trusses, it's the trusses and and joists as well. All of the things that compromised one of the floors of the building. I think it's pretty clear what NIST is talking about when they talk about an intact floor of the building. That's what I'm talking about.

so your answer to Henkka is "yes, the floor we walk on is where we are laying the weight." yes?
(some people use the word floor to mean a whole story of a building, although how you lay a block on a whole story im not sure)

 

[benthamitemetric]

so your answer to Henkka is "yes, the floor we walk on is where we are laying the weight." yes?
(some people use the word floor to mean a whole story of a building, although how you lay a block on a whole story im not sure)

Yes, that's right. The only quibble I have with Henkaa's description is that it could be read to be just the concrete part, when I am talking about the whole floor system. But you have the right idea. I appreciate the clarification.

 

[Mendel]

My sense of structures like this is that they're integrated to distribute loads in all directions as needed.

Yes, but only in the system working together as a whole. This is not true if you single out parts, or damage the system.

 

[Mendel]

It would be the velocity that would have to decrease in order for that kinetic energy to be used to break apart anything. But it didn't.

Force breaks stuff.
Force is equivalent to acceleration.
The fact that the descent was not at 1g tells you that some energy got converted into destruction.

 

[Thomas B]

Yes, but only in the system working together as a whole. This is not true if you single out parts, or damage the system.

The question is, How was the system broken? How were the parts singled out? What caused the system to stop working as a whole?