I was out with a friend the other day in a newer Chevy Trail Blazer with OEM aluminum wheels and we experienced a flat. There was no puncture in the tire and the bead was intact. The cause was a crack in the rim. The crack was on the backside inside of the wheel. We were off-road and the ground was soft to firm mud and hardpack dirt. This puzzled me. I've never heard of this happening. When I explained this to another friend he said that the driver probably hit something hard (ie. a curb) while driving in the city (since the vehicle is predominantly driven on pavement). This got me to wondering about the strength and integrity of Jeep OEM cast aluminum wheels. Has anyone heard of this type of wheel failure or experienced it themselves? If so, what caused it?