Pieces of steel in cylinder??

Great Explanation, oil for boundry layer got squeezed out from the extream high pressure of the piston bottoming out against the seat material sending the presure down to the crank bearings.

The bearings are the weak link in the rotating assembly to hammer out first and protect that important crank shaft when things go bad.

The Bearings did their job, protecting critical machine work around them.

The bearings will also heat up when the boundary layer lubrication is lost because there is no oil to keep them cool...