[Buddahaid]

Originally Posted by Betonov

I believe it was the iron that became brittle in cold. But then again, rivets were also iron. It was a mistake made by designers and managers.
I'm surprised the whole thing was not built of steel, it was mass produced in those times IIRC.

It was a gamble to use cheaper iron to cut costs and the innocent paid with their lives. That's not a mistake but a decision based on profits and the unlikelyhood of meeting just such a disaster. Still happens all the time.