If you have ever read"Why Buildings fall Down" by Matthys Levy and Mario Salvadori you know that discovery through previous failures can be very illuminating. I think the crane incident in NY is true to this idea.
This is a link that has a good illustration on the failure:
one of the thoughts I had on seeing this is that it is a situation where it looks at first like there are multiple points of failure needed (which is true), yet, the failure of one puts the other elements at risk of failure due to the design.
More places to look into things that have failed is by watching Engineering Disasters, and by checking out this blog: