Why they dont immediately remove rubble from a building collapse when one occurs.


Why they dont immediately remove rubble from a building collapse when one occurs.

In: Engineering

I’m no engineer but I believe two reasons: 1) They have to do a search and rescue. Just going in hog wild and removing debris could lead to further collapse, which plays into 2) They have to do it in a certain way to prevent further collapse and risking the lives of first responders.

You mean after the immediate search and rescue / making sure it won’t further collapse operations are over?

Same reason they don’t immediately remove a dead body from a potential murder scene and bury it.

Gotta figure out what happened – insurance companies, lawyers etc. send their experts to investigate the rubble. To figure out why the building collapsed, if there is someone to blame, to figure out who has to take responsibility. If they would just remove it and clean up immediately they would basically destroy potential evidence.

Because death-by-Jenga-collapse is basically manslaughter.

You can’t just pile in and shift hundreds of tons of collapsed rubble without it moving underneath you, potentially killing anyone who’s surviving in a small pocket underneath. People can and do live for days in such scenarios, and it’s better to recover them safely than find out that you caused a collapse which killed someone who would have been relatively uninjured.

Also, what you want in those circumstances is SILENCE. Every now and again you must ALL stop work, to listen for cries of survivors so you know where to focus your efforts, even if all you can do is reassure them or get water to them, it’ll extend their life by days, sometimes weeks.

It could be holding up “triangles of life” which survivors could be in. Taking the pressure away could collapse it
Then there’s rescuer risk, and the fact there’s usually live wires and fire risks in the rubble as well.

Adding on to many other helpful comments: most people don’t realize that excavators and other heavy machinery essentially do their job by pushing large amounts of material around. So, even if you identify someone trapped in the rubble in a place where further structural collapses aren’t a problem, you have to dig them out by hand. Using machinery will just shove more debris onto them, crushing them to death.

Incidentally this is often the mistake people make when workers are trapped by mounds of dirt in collapsed trenches, or other dig sites. Trying to dig them out with an excavator is more likely to get them killed than not. You have to use a shovel.

Also, after all the search and rescue operations are complete, and the investigations by a number of agencies and even insurance companies, (like all the other commenters have said) you still have to actually remove the debris.

The big side dump trucks only hold 14 cubic yards per trip. So you need to be able to hire enough trucks, and have a place to dump everything. All of this takes money and coordination that often can’t occur until the insurance pays out.

For example, the 9/11 debris wasn’t fully cleared until May 2002, and took 108,000 truckloads-1.8 million tons. Where I live, tipping fees are $169 per ton at the landfill… so just clearing the debris was a multi-billion dollar operation.

You know that giant arch in St. Louis? Imagine if you took a giant 10 foot chunk out of the top most section center of that arch. What would happen to the rest of that gigantic structure? It’d fall in on itself. Collapsed buildings are far more complex bits and mess that are all resting against each other and there are possibly people under them. So if they take a random thing out, that could cause even the slightest of collapses underneath possibly killing a person pinned in a pocket. Additionally adjusting the weight anywhere can do the same thing so the bits don’t even have to be intertwined, just resting on top. Engineers are trained essentially to treat the pile like a Jenga game, they find the bits that have the least influence on the debri and try to remove them, they also have equipment that scans far into the mess to try to find bodies and people first so they know if an area is safe to disturb slightly.


Ignoring the search and rescue aspect, as that’s been addressed by others, they can’t just scoop up the rubble and dump it in a landfill.

First, there’s the possibility, even the likelihood, of toxic materials. Asbestos was fairly commonly used until the 1980s, but even newer buildings could have mold, pockets of carbon monoxide, spilled bleach and windex that would create a poison gas. Lots of stuff.

Second, some of the materials are worth saving. Copper pipes and steel rebar, for example, will be separated out and recycled.

Third, there’s a safety aspect of just moving tons of material. You can’t just ram a bulldozer into a three-story tall pile of rubble, not can you drive an excavator on top of it. So it’s logistically challenging.

Turn off and secure utilities (Water, Gas, Electric)

Search and rescue people.

Recover property that might not be damaged or hold sentimental value.

Investigate the cause of the collapse. This is usually the most important one why it’s not removed. Insurance may be invalidated if it’s removed strait away as no cause of the incident has been established and all evidence would have been removed.

Once a cause has been established, the Insurance company will then pay to have everything removed and rebuilt.

Because you have to make sure that you’re not going to cause the rubble to settle by removing the debris in the wrong way. You may have people who are still alive in there, because the rubble fell in a way that they have a pocket of space where they’re safe. If you start taking out debris randomly, you might accidentally remove a piece that is actually supporting that void and keeping their pocket of space open, causing other material to crush them.

After the Oklahoma City bombing, it took 17 days to recover the bodies of all but three of the victims. The rest of the building was deemed too unstable and was slated for demolition. The demolition was delayed for a few weeks to give defense lawyers an opportunity to examine the wreckage. It was only after demolition that the big trucks came in to remove the debris and recover the remaining three bodies.

So we may have a similar situation in Florida, where the rest of the building will be demolished before removing the debris.

Put your hand on a big rock and then put another rock on top of it. The top rock may be heavy, but your hand is still okay. If you put more rocks on top of that, your hand has the ability to withstand a tremendous amount of weight. If you want your hand back, you want to carefully remove the rocks on top of your hand. If you try to pull your hand out from under the rocks, you’re going to do more damage.

Rubble isn’t able to be removed carefully, without risk, and without disruption of what’s below it. There may be survivors in small pockets or be trapped by pressure of rocks on top of them. Removing the rubble is like pulling your hand out…it can cause more damage. The best chance for victims is to find where they are and mindfully remove the rocks on top of them, without injuring or killing them in the process.