Causes of engine block crack?

Could’ve been pre-ignition. Engine didn’t have any knock when it was running. But could that cause the cylinder wall to split like that? What came first? Cracked block or destroyed piston? Who knows
You're not going to crack a cylinder wall with some street pinging. If it was detonating.. it would be felt ar surging, coughing, and noise.

The hone looks rough enough to hold oil, so no overheating.