All of the Ways Underground Bunkers Can Kill You

Avatar for Jodie Weston Jodie Weston  |  Updated: September 5, 2020
All of the Ways Underground Bunkers Can Kill You

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When people think of crazy preppers, they often think of underground bunkers, full to the brim with supplies, locked up beneath a Fallout-style hatch. But few of us have, or want bunkers. Why? It’s not exactly something you can build for cheap.

If you can afford to pay professionals to build one for you, sure, I suppose it could come in handy. These can run from $40,000 to over a million dollars though. To cut costs, some people try to do it themselves, but that is a really, really bad idea.

bunker world war

Without expertise, your bunker will just be a death trap. We’re about to point out all of the reasons why. The next time someone hears you’re a prepper and wants to talk to you about their make-shift bunker, you can send them this article.

1. Collecting Gas

Many harmful gases are heavier than air, and will collect in your bunker unless you take precautions.

Even if the gas itself can’t kill you, it will push out oxygen until you have nothing left to breathe, and that will kill you. Scenarios that people commonly prep for can involve gas release, like domestic unrest, war, and more.

Imagine pulling tear gas into your bunker. Then you should consider pandemic prep, if you want to use outside air you need a filter system. Or, you could consider gas leaks that wouldn’t normally merit a SHTF situation. A simple nearby propane leak, off-gassing from nearby septic tanks, or off-gassing from the soil itself, could all kill you.

2. Collecting Water


It’s not just about keeping rain water out of the bunker. It’s that you want to bury the bunker nice and deep to protect it from surface impact. But, you’re limited by the depth of your water table.

If it’s at all below the level of the water table, it will flood, concrete, steel, or other materials be damned. Sure, there is some top-notch engineering you can do to keep the water out, but it’s expensive. One solution is to put the bunker at ground level and then pile dirt on top of it, but you need very large amount of dirt to protect it from impact.

3. Impact


Speaking of sustaining impact, a bunker won’t survive the big one. Large earthquakes will certainly unseat it. Perhaps that’s not what you’re prepping for, but if you live in an Earthquake zone that’s something to think about.

If you have a bunker in the blast radius of a nuclear bomb, (the usual rationale for a bunker), it won’t survive. And, because you’ll have very little notice, if any, in the case of a nuclear bomb or explosion, you’ll have to be near your bunker when it goes off. Which means those of you who live in a potential attack location probably won’t be saved by a bunker.

4. Cave-In

You should use a competent engineer, preferably one with experience with subterranean buildings, to help plan your bunker. If not, it will probably cave-in.

Using old mine shafts or putting a shipping container into the ground (two strategies I’ve actually heard people try!) are two other good ways to get crushed to death. Another is to have a fire in the bunker. If you’ve made it out of steel, it will become more elastic and weaker under the heat and then buckle under the weight of the ground.

5. Steel

There’s another problem with using steel, in general, and that is that it corrodes when placed underground. You will want thick steel (that a shipping container just doesn’t provide), or you can avoid the problem by using a different material.

If you’re going to try to use steel in your own build anyway, try reading this technical manual about how to prevent steel corrosion (in pipe systems). In short: it’s tough.

6. Fire

There’s going to be a fire risk in your bunker, and it could even be in the walls. Many professional companies use Expanded Polystyrme (EPS) foam blocks which, according to Clarence Mason of Tempest Building Systems, are highly flammable and full of toxic chemicals in an attempt to make it less flammable. They should, ideally, be encased with something that is not flammable, but because they’re used in part to reduce costs, you might be tempted not to.

fire burning

The rest of the fire risk will be from all of the things you bring into the bunker. Your power system could spark a fire, and your supplies could provide it fuel. And while you’ll probably (hopefully) also have fire extinguishers in your bunker, even a small fire could be a serious risk for the oxygen levels in your bunker. Fire uses oxygen, and you need to be sure your ventilation system can replenish that oxygen very quickly.

7. Air Quality

Speaking of ventilation systems, your bunker’s air supply is absolutely essential. What’s that saying: you can only last three seconds without air? Yeah, and plenty of things other than fire can interfere with your air supply.

Firstly, you need two ventilation systems, in case one breaks beyond repair while you’re in the bunker. Second, you need to protect the vents from birds, debris, and weather on the outside.

Then, you need to filter the air itself for many SHTF scenarios, including to protect from radiation, or people walking by who are infected from the pandemic, or debris from nearby collapsed buildings, the list goes on.

8. Moisture Control

Depending on your environment, moisture control could be a large component of your air quality system. If you don’t get moisture under control, you’ll get mold.

That may not be a life or death scenario, but it could certainly make life uncomfortable. And, long-term exposure to some molds has been thought to cause respiratory issues, perhaps leading to death, but the research on that isn’t in yet, as far as I’m aware. Either way, mold is not something you want.

9. Escape and Access

If there is a fire, flood, or other problem in your bunker, you will need a way to get out. Problem is, most bunkers people envision have only one escape hatch! If that’s blocked, you’ll die.

Plus, you also have to think about how you could get out of the bunker if you’re wounded. Let’s say it’s not SHTF and you’re stocking your bunker. You trip on supplies, or what have you, and you break your leg.

bunker underground

How do you get out? Not only can you not get yourself out, but I bet you don’t have cell service down there. If you do, and you call for help, paramedics can’t get a stretcher up and down a bunker’s shaft.

The fire department is going to have to use a pulley (and will fine you for creating this monstrosity while they’re at it). If SHTF has hit the fan, without someone on the outside to help you out, well, you better hope you can address your leg inside the bunker and survive there until your leg can bear some weight.

10. Floating

It sounds crazy, but your bunker might start to “float” in the ground. If it’s not heavy enough, the pressure from the ground, when wet, will push the whole bunker right up out of the ground.

It’ll emerge like Venus from the sea, alerting everyone to its presence, and creating a huge hassle for you. If SHTF already, this could end your life. Some light bunkers are designed with skirts to hold them down and avoid this problem.

11. Radiation

Protection from radiation is a bit more complicated than most bunker-enthusiasts first think. Yes, you should use concrete as protection, but you have to understand how it works. Concrete doesn’t reflect radiation, it absorbs it. And when it fills up, you’re exposed, and that could mean death, depending on the dose you receive.

Manufacturers make special kinds of heavy concrete that absorb more radiation, usually for nuclear waste storage facilities. But ultimately, you’ll need a very thick layer of concrete, not only for the walls but above and below you. It’s important to calculate how much radiation your bunker will need to absorb in the worst-case scenario you’re prepping for.

12. Waste Disposal

Of course, that always over-looked question of “where should I put my waste?” is even more pressing when you’re in an underground bunker. You could rig up a humanure set up underground, but that would be challenging for space.

So would a septic tank, and what happens when that’s full? Plus, you’ll have paper and plastic waste as you go through your food supplies, and you’ll need a separate place to put that kind of waste.

Without a very in-depth system, you’ll be bringing your waste out of the bunker. And that’s risky, drawing attention to you and your supplies. Of course, without proper sanitation you could easily die of infection, off-gassing, and more.

13. Vulnerability to Scavengers

You’re always vulnerable to scavengers in a bad enough SHTF scenario. But there are special risks in a bunker. If you’ve used professionals to help you build this bunker, which you should, they will likely know where it is.

bunker scavenger

If you’ve constructed a big enough bunker and not disguised it well, your neighbors will know where it is too. And those who are reasonably sure a bunker is somewhere in your area could use a metal detector to try to locate you. Usually, this works because bunkers are put in metal Faraday cages to protect from EMPs.

Any of these people can team up with others and attack you, perhaps even when you’re unaware. They’ll be very motivated because they’ll know you have a lot of supplies. And if Rule of Law has collapsed they may not care that they signed a confidentiality agreement.

14. Psychological Distress

When planning for our survival we sometimes forget to think about our comfort. A deeply uncomfortable situation, however, will risk your psychological health and therefore your life. Some people do very poorly in small spaces. Some struggle in close quarters with other people, some struggle without people.

You won’t have much room to exercise, you won’t have as much entertainment as you’re used to, and you won’t have access to the sky. That last one is a big deal, sunlight helps keep our circadian rhythms going and without it, you’ll bounce into a rhythm just slightly off our usual 24 hour rhythm.

That will mess up your day counter, which is absolutely essential to get right if you are waiting for radiation to dissipate, for example. For that reason, you need something to keep track of time. A light dimmer set to follow morning and evening plans would help too.

girl crying pain

How does psychological discomfort risk your safety? You don’t have to go stark raving mad to make poor decisions because you’re uncomfortable. You might, for example, convince yourself that a short walk outside the bunker is what you need to feel better.

Sure, but that could risk your life. You might try to compensate for your discomfort by eating more food than necessary, or with any kind of behavior that might annoy the other people in the bunker with you. That could lead to conflict, which could make your situation a lot worse.

Final Thoughts

Bunkers can be done well, but like all things prepper, be realistic about it or don’t consider yourself prepared. This isn’t a complete list, you’re going to need to consult some experts! And, be suspicious of bunkers offered on the cheap—chances are they haven’t considered everything they should.

Do you have a bunker? Do you know someone who has tried to construct one themselves?  

Author Bio: Ellysa Chenery can be found writing all over the web. She loves adapting traditional skills for new situations, whether in the wilderness, garden, or homestead. Her favorite smell is carrots fresh from the dirt.

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20 Responses to “All of the Ways Underground Bunkers Can Kill You”

  1. I am 68 & my friend is 62 and we want prep as for building a place to live under ground or above we have no to help us i am trying the best i can!! Plus we have 4 dogs & 1 cat, which we have to think about! I have an idea of what we would need to
    survive. I was brought up by grandparents who knew what it took to survive. I will do what I can that have to be enough!

  2. Murphy’s Law of Combat #37
    “Make it too tough for the enemy to get in, and you won’t be able to get out.”

  3. I took s course related to radiation years, ago. It stressed using multi levels of protection, earth, concrete etc for an initial blast, waiting for the rad levels to drop, then maximizing you efforts to create as much distance and time between yourself and the affected area, to reduce your exposure re fallout and
    contamination. Personally i think
    If it ever happened there would be multiple exchanges e.g the Russian automated doomsday method. You might…. a very big….might, survive the first, but not the 2nd, 3rd, 4th etc…

  4. “All the ways…”? I’m sure that we can think of a few more. Paul Simon could probably rhyme “50 ways your bunker killed you”.
    Your food went bad, Dad.
    Your water ran out, Scout.
    You didn’t try to run, Hon.
    You couldn’t evac, Jack.
    Your batteries blew, Lou.
    Couldn’t pay for the Doc, Jacques; you spent it all here.

  5. I’m only interested in above-ground bunkers.

    When can you write another article, this time on above-ground bunkers?

  6. My question is, if the situation requires a bunker to survive, what is there to survive for? What is left of the world you know and normally live in?

    • My dad was a USN Seabee, who’s unit moved into Nagasaki, after the blast. He thought that most people,would find the post blast world extremely traumatizing and physically demanding. His comment re 1960s Hydrogen bomb which has since been eclipsed a thousandfold at least. The article didn’t address dealing with a Neutron bomb, which is designed to leave infrastructure intact, but intended instead to penetrate such deeply, to create cell damage to living organisms.

  7. Concrete doesn’t absorb radiation like a sponge – so it can’t fill up. But what CAN happen is that with enough radiation damage the concrete will start to degrade and lose some of it’s structural strength. Of course that takes a LOT of radiation, probably more than is survivable by anyone inside any reasonable thickness bunker.
    Reference: //
    Mass is what blocks radiation. Concrete is useful because it’s both dense and strong, so it gets used in a lot of bunker construction. Steel is also useful, but it can become radioactive itself by neutron activation. (So close to ground zero, you’ll need to protect the steel from neutrons – boron or water are the most common ways to reduce neutron flux damage to the protected space.) But there is no reason you can’t use lots of dirt, water, stone, etc. Anything that has mass will attenuate radiation.
    That said, a professional bunker is your best bet. Build it yourself may work as a shelter outside blast or impact zones, but as this article points out, there are plenty of ways to kill yourself that don’t involve fire or radiation…

    • Neutrons are emitted only during an active fission process, such as that taking place in a nuclear reactor or at the actual moment of an atomic explosion. Neutron activation that is structurally significant takes many years, and is only a concern in materials that will be used to construct things like nuclear reactor vessels. This is in no way a concern when choosing structural material for a shelter.

      The radiation of most concern for shelter inhabitants will be gamma radiation.

  8. I’ve known two families with fallout/blast shelters, both 1950s vintage. One was built in the basement of an existing house, and was strictly a fallout shelter. Cement blocks, and and a corridor entrance with two angles, something like the entrances one sees today in airport bathrooms. I don’t remember what they used for the ceiling, tho we used to play in it as kids. It had a hand crank ventilation system, which IIRC used a whale of a lot of arm power for the amount of air it moved.

    I never saw the other one, but it was described to me a few years ago by the son of the builders after the house was sold and security no longer an issue. He said his father was concerned about nuclear war, and that he was also worried that the house would burn down as a result of the blast. His solution was to have an underground blast shelter built outside the house, with a corridor entrance from the basement and another exit in case the house burned/collapsed. Yes, this was a very high budget bunker.

    I know of another room which may have been thought of as a bunker…or maybe not. A couple built a house with a full basement and an attached two car garage which has a concrete slab floor. Under that slab is a ‘storage room’, entered from the basement, but it has a concrete wall between it and the rest of the basement, and a steel door which opens inward. Sound like a bunker?

    Given that radiation shielding can be created both by putting mass between you and the radiation source, or by putting distance between, a basement fallout shelter doesn’t have to be terrifically expensive, even with a retrofit. Build a room in the middle of the basement for distance shielding.

    New construction: if there is going to be a full basement, pour a slab floor for the space above the shelter. That assumes of course that the house is not in an expected blast zone, because a proper blast shelter drives up the costs considerably.

    Another possibility is a pre-fab concrete tornado shelter delivered to your site. They can double as storage sheds in good times, including as pool houses. Google ‘precast concrete storm shelter’ and variations on that. Anything which can stand up to a tornado would stand up to a fair blast. Not ground zero, but if you are worried about nuclear war, you probably don’t live at ground zero.

    If you live in an area hospitable to tornados, you might want one anyway!

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