Sorry for this, i'm being a bit 'post happy'
But,
I am wondering if there are any interesting cases
where the issue of stress analysis(of lack off)
was instrumental in the failure of piping systems.

What got me thinking here is the recent chemical safety board video on the recent BP explosion
http://powerlink.powerstream.net/002/00174/051222bp/BPAnimations.asx

the video refers to the Relief devices operating.

'History is a good teacher'