Sparks are a major hazard in a lot of industries, to the extent that there is a full range of non-sparking tools made from high-strength copper alloys. They're most often used in the oil, gas and petrochemicals industries, but they're also used in dry and dusty environments like grain elevators and flour mills.

https://www.avensafetytools.com/product-category/non-sparkin...

I have no idea whether this story is the whole truth, but it's perfectly plausible - in extremely dry conditions, a tiny ember can become an uncontrollable fire in a matter of seconds. The speed of a grass fire can be truly frightening. Take a look at this video:

https://youtu.be/F79tkSKstxY?t=10

The fire in that video was started by the heat of an exhaust pipe, but it could have just as easily been caused by a spark or a cigarette butt. If a fire like this started in front of you, how sure are you that you'd be able to extinguish it single-handedly? What if it started behind you and it got a head start of a few seconds before you noticed it? If you were dressed in shorts and sandals rather than fire-resistant boots and overalls, would you even stand a chance?

A moment of hesitation or distraction is all it takes to lose control of a grass fire. Based on the account given, I can fully imagine the desperate and ultimately futile effort made to extinguish a fire that rapidly spread out of control.

That video is incredible. It's hard to estimate size from the shaky footage late in the video, but I would say the fire grows to be almost 50 meters wide in the course of... three minutes? And that's with a dozen men trying to fight it. I was looking at some other grass fire videos and found a great demonstration by a fire department [1]. It's pretty clear that even on a calm day in short grass your window to stamp out an accidental fire is perhaps 10 seconds.

1: https://www.youtube.com/watch?v=rcYVt0DMlos

The video in your second link shows just how hard those grass fires can be to contain. There's what, a half-dozen to dozen riders present? And despite their effort, it continues to spread throughout the video.

Most people severely underestimate the speed of fire and overestimate the speed at which they can respond. Even if a fire looks tiny, you have a very narrow window of opportunity to react before the fire spreads beyond your ability to control.

The same applies to fire in the home - if you can't put it out right now with whatever comes to hand, you've probably lost your window of opportunity to fight the fire. If your sofa or curtains catch fire, there simply isn't time to fill a bucket or fetch a hose. If you don't have an extinguisher to hand and can't snuff out the flames with a blanket, you need to run.

https://youtu.be/w4W82HIzUcc?t=78

I was amazed how quickly all the riders reacted and also recognized it wasn’t going to be easy to get out - “we’re not going to stop that with camelbacks”!

I once broke into a restaurant and put out a fire which would have gone critical before the firefighters arrived. Towels and dishrags. By the time they did, it was out. Likewise once when my car caught fire in the engine room. Buckets of water from the cleaner in the adjacent supermarket.

You often do stand a chance if you keep your wits, assess the situation, and act sensibly without any delay. I know everything is easy from my armchair, but can't help noticing how in the grassfire video nobody seems to be doing anything worthwhile while the thing is still manageable. In that kind of dry grass, jackets should have come off and smothered the fire within the first seconds, no panic and no danger.

Fire can get outa hand say farmers that burn ditches and wheat fields after harvest. Add a little bit of wind and you cannot even approach the fire, might need to stay 5-10 yards away. Go ahead and stop that one then :).

Best bet, if possible, would be to improvise a barrier xx meters away so when the fire reaches there it stops by itself. Easier said than done.

Those tools suck. Nobody who's not working in an environment saturated with volatile hydrocarbons should be using them. Seriously, they might as well be made of butter compared to normal steel tools. Seriously. 0/10. Do not recommend. I guess the hammers are ok though since they're basically just a metal lump.

I find both your comment and jandrese's comment perfectly convincing. So now I'm horribly confused and I have no idea who is right. I guess there just isn't enough information to rely on to figure out what exactly happened?

No need of silencer, you can put your leg on the side stand to touch the asphalt road slightly and it will create tons of spark. Same is true for concrete with less intense sparks depending on the composition

> There's probably no way to prove it either way.

Fire investigators can trace back the origin of fires. I know in some cases they can trace it back to a specific outlet in a home.

Would the investigators not be able to see the point of origin has a 24 inch concrete stake driven in to the ground? Would they not be able to see there was an overturned 4-wheeler? This story sounds so unbelievable that I’d expect trained investigators to be able to find the obvious holes (I swear, no pun was intended).

> I know in some cases they can trace it back to a specific outlet in a home.

It's not even hard. When I had a fire in my apartment while I was away, the inspector simply was actually really nice when we went through an explained everything in the aftermath:

"See that "V" on the wall, that tells me the fire started here at this outlet. Note that the books you had on this shelf are charred, but not fully burned. Books are pretty lousy in terms of going up in flames. Note the books on this side, they're totally burned. Accelerant--you probably kept oil in the cupboard above them. You clearly had something heavy in this cabinet, cast iron? ..."

And he just went on and on as he walked through. If you ever want to try to commit insurance fraud by setting a fire .. don't. The inspector will know--he may not be able to prove it, but he will know.

>>If you ever want to try to commit insurance fraud by setting a fire .. don't. The inspector will know--he may not be able to prove it, but he will know.

Morals aside, people will do and quite a few will get away with it. Average Joe should not, but for every fire inspector there's a smart crook.

A lot of criminal cases were thrown out because the forensic science was proven to be incorrect.

http://www.abajournal.com/magazine/article/long_held_beliefs...

A concrete stake is not _made_ of concrete. It is made of steel.

Indeed. They are steel stakes used to set forms to pour concrete.

They look like this: https://d323w7klwy72q3.cloudfront.net/i/a/2012/20120125midwe...

You can definitely make sparks from metal-on-rock contact, FWIW. Concrete contains gravel for filler material etc.

For sure. I see it when I work in my yard late into the summer. As it gets dark I've made sparks with shovels, picks and quite often the teeth on the excavator bucket will scrape a rock and make some pretty good sparks.

It can be done on concrete. I've split logs for firewood on concrete before. Sometimes the wood is more cooperative than anticipated, and so the the axe goes right on through the log like it's not there, and kisses the concrete. There's sometimes a spark or two when it happens.

Steel tools on concrete can definitely make sparks. I assume it requires the aggregate in the concrete to be hard or the concrete to be very old and therefore hard. I’ve noticed this when breaking up concrete at night, a horrible chore.

It can be done on concrete if rocks are mixed in, not uncommon.

there are plenty of ferrous iron/steel concretes.

I use them for pads for my heavy equipment because it doesn't move much after the initial setting.