I doubt it's another steel manufacturer but who knows? Maybe someone in the business with connections to black hats had some money to spare and said: Look what you can get going about this cyberwar stuff everyone is talking about...

There is also this: http://www.heise.de/security/meldung/Verwundbare-Industriean... (In german)

I have to admire your cynicism. To consider that this attack might have been nothing more than a sales demonstration...

That's a scary thought, even as it sounds like something out of a James Bond film script.

Why does it have to be someone with a solid motive?

The companies attacked always go on about how skilled and unstoppable their attackers are, but for all we know their software was terrible and a bored 13-year-old shut down their factory because 13-year-olds do terrible things for no reason because the parts of their brains that let them tell good ideas from bad ideas haven't grown in yet.

The guy responsible for the shit software isn't going to tell the CTO his software is shit, the CTO isn't going to tell the CEO his department is incompetent and needs a good house cleaning, starting from the top, and the CEO isn't going to admit culpability to the insurance companies and shareholders who are ultimately on the hook for the damages.

Bored 13 year olds usually try to be flashy or show off, but they rarely spend significant effort really causing damage.

There's just nothing in it for them to actually cause damage, when demonstrating the potential to do so (without actually doing so) provides all the benefits (bragging, etc.) with much less risk.

Yes, you can have one deranged person doing it, but it's just not likely.

But your 13 year old may not understand the possible real-world effects of their hacking. They could just be playing and made a mistake.