My guess... since this just happened to me, and I was able to diagnose the problem with the help of the LBS:
Your chain wasnt installed properly, and the special link's pin came out a teensy bit. The pin caught on the derailieur pulled it forward, snapped the hangar, got thrown into the spokes... etc.
I'd bet a dollar its the pin on the chain. Check the chain... and if it hasnt been touched since you bought the bike, it could be your LBS's fault...
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2008 Cannondale System Six
2016 Pivot Mach 5.5