Help...broken oil dipstick caused engine failure

[nicke]

So I have figure out what happened to my 350 on my 71 C20. The dipstick wasn't the correct one for the engine, it was too long. I am not sure what it is out of. As I was driving I noticed a power loss for a second then a loud bang, and the engine gave out. I coasted to the shoulder and the engine wouldn't even turn over...it acted as if it was siezed. Upon inspection, there was no external damage, and I tried to check to see if there was oil in it. When I pulled the dipstick out, I noticed that it had been broken off inside the engine.

What damage might I have caused? Crank?...everything???
Has anyone ever heard of this happening?

Thanks for your help with this.