Duramax bites the dust - Blown head gasket @ 102K miles

I to have heard of people having head gasket problems, but we have have 12 LLY's in between family and friends and company trucks and never had a overheat light or gauge come on. We are out in the Las Vegas heat going to California up and down that Baker Grade all year long for fun and work Not One Problem. The company one we have now has 250,000+ and still trucking along. My 05 personal one has 40,000 on it so I can't speak to much for that one working hard lol.