I've broken three
All homerolled 9wts with poorly matched sections
It got to the point where Bob at H&H would just send me out a new blank whenever I called... no questions asked. A few free components too for my trouble.

I watched my fishing partner break a rod two seasons ago
The feeling of helplessness was worse that if I did it myself
He was trying to land a striper of about 20# in very heavy current
I tried to yell at him that his rod, a St Croix Legend 10wt, was dangerously bent over.
He had his mind on the fish and paid no attention to me
Snap!
It made for a good picture anyway