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Comment by manmal | Hacker News Reader

Please bear in mind that I don’t mean the following in a cynic way. Damage from storms is horrible, and I feel for the families losing their homes every year.

There was a tornado just a few days ago in the Czech Republic (not far from where I live), and as far as I can see, houses did lose their roofs, or the shingles at least, but the structures remained mostly intact. Many houses have basements in which people could hide in relative safety. Five people died unfortunately, not sure how many of those were in their homes at the time. But I think those rather sturdy houses made of bricks did infact save a lot of lives, and prevented many more from totally losing their home.

To me it feels deeply illogical to build a house basically made of light wood frames when I know a hurricane can blow it away while I‘m inside of it. I‘m not sure about earthquakes, we have them of course, but they are less severe than in other areas in the world.

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I just looked that up and that appears to have been an EF2 tornado. That intensity deals an order of magnitude less damage than the EF3, EF4, and EF5 tornadoes that regularly appear in the US, which can literally tear entire houses off their foundations. A brick building in those conditions would be reduced to individual bricks.

I read it was estimated to be F4. Brick houses are definitely less likely to be destroyed than timber.

Timber can be many things. I have a hard time seeing a log house being swept away by almost any force of wind.

Then you don't appreciate the forces at play. An EF4 will rip deep rooted trees right out of the ground.

I can see that there are manufacturers selling log houses certified for cat-5 (245 mph) hurricanes. I do of course understand that any construction will be blown away at some point, I just cant picture it. The way the logs lock each other at the intersections and how the structure still is sound with no roof should help quite a bit.

The big danger in a cat 5 is more the debris.

There's a saying: It's not THAT the wind is blowing,it's WHAT the wind is blowing.

I worked on a cleanup crew after hurricane Andrew. Huge H-frame metal girders on highway structures were bent like pretzels. Entire lime groves were uprooted and piled like tumbleweeds. Houses were completely exploded. It was similar to what I imagine a bomb going off would look like.

A log cabin would not have survived the worst areas of it I don't believe.

Hurricanes and earthquakes are one thing, but what percentage of the US population lives in areas regularly subject to EF3-5 tornadoes?

Much of the Midwest, which is 21% of the US population.

Hurricanes are far more destructive and many spawn tornadoes. About 44% of Americans live in a Hurricane zone.

Add earthquakes and fires maybe 60~70% of Americans live in a place with reoccurring natural disasters.

You might be surprised: https://worldpopulationreview.com/state-rankings/tornado-all...

EF4 or EF5 tornadoes are around 2% of those in the US (https://en.wikipedia.org/wiki/Tornadoes_in_the_United_States), which means any state with more than 34 or so a year can expect to see at least one. That accounts for 14 states with a combined population of about 106 million people. That's approximately 32% of the total US population.

8%-ish of tornadoes rate EF3. At which point any state with seven or more a year should expect at least one in the EF3-5 range (yay, birthday paradox!). That's 32 states totaling 270 million people - 82% of the US.

I find a flaw in your logic, but don't have a pithy name for it. Population densities and EF4/EF5 tornado probabilities are not uniformly distributed throughout a state, and probably are negatively correlated.

Looking at this image (https://en.wikipedia.org/wiki/File:Improved_Average_Annual_T...) from the wikipedia article you linked shows this, with New Orleans, Atlanta and Miami being outside their state's main tornado zone and Houston and Chicago right at the border of high-tornados and medium-tornados.

Oh, you're absolutely right. I simplified immensely by aggregating at the level of a convenient political division that has only vague bearing on actual geography as well as assuming the distributions are uniform across the range in question.

I think the overall point is sound, though. A huge chunk of the US population is in territory regularly subject to strong tornadoes.

Also, I would beg to differ that this map puts Chicago at the edge of a high-tornado zone. It's solidly in one, as is Kansas City.

I agree with KC. For Chicago, it looked to me like the tornado zone had a small buffer around the lake that Chicago nestled into.

But your larger point stands.

EF2 is not a measure of force of wind. It's a measure of total damage. . The wind speed was in the F4 category.

The frequency and maximum strength of tornadoes are higher in the central US. Casual skim of the wikipedia page indicates about as many F4 tornadoes in Europe as F5 tornadoes in the US since 2000.

There are many tornadoes where I live and most of the houses don’t have basements. Directly in the path of the tornado, houses built on a slab were completely gone, leaving only a clean slab. This happened to a few entire neighborhoods.

But, tornadoes here follow similar paths over a fifty year period. When I bought my house I found a hole in the fifty year tornado map and I’ve never had one come near me. Every couple decades the patterns may shift to other patterns, but generally speaking both the new patterns and old patterns have all happened in the last fifty years.

That’s devastating. I wonder why houses in such areas are not required to provide underground shelter, or at least be built more solidly.

You cannot reasonably build solidly enough to withstand a high-level tornado unless you're talking underground bunkers, which are not an acceptable answer.

Is it not?

For a few decades the Swiss required building concrete nuclear fallout bunkers for every resident. This was relaxed only recently, but presumably it was doable for five decades. https://www.reuters.com/article/us-swiss-bunker/swiss-relax-...

So you can be in a bunker above ground. At that point you're quibbling.

That’s a bit defeatist, though? Efforts have been made, eg https://tigerprints.clemson.edu/cgi/viewcontent.cgi?article=...

It seems a concrete dome would also work if digging a bunker is too expensive. Yes it’s not pretty, but not being afraid of dying during the next hurricane season must be worth something. A small dome can’t cost much.

Sure. Building a reinforced shelter for tornadoes, nuclear attack, etc. may make sense. Historically, in the US Midwest that meant going into the basement. But you don't live there.

It's not a problem, people just don't want to pay for it.

https://www.icfmag.com/2012/09/tornado-resistant-concrete-ho...

There aren't many natural disasters a sufficient amount of reinforced concrete can't fend off.

Many places the basement would be under the water table or have to be carved out.

After the 2011 tornadoes in the Southeast US, many communities built above-ground shelters (think "bunker"), with the downside being going any distance to a shelter is likely to be more dangerous than staying where you are. Also, many homeowners bought smaller above-ground shelters (think "steel pill-box").

> I found a hole in the fifty year tornado map

What was your source for this information?

Well, the three little pigs story must have been originated somehow from real life experience:

https://en.wikipedia.org/wiki/The_Three_Little_Pigs

Insurance is federally subsidized/backstopped so people in hurricane or tornado zones don't have to pay for repairs directly, so it's cheaper to build a junk house than one which wouldn't take damage.

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