That looks to me like a broken ring land due to catastrophic knock or pre ignition which butts the rings. Hard to say what came first the broken piston or the cracked block but it’s a mess regardless.
Pistons breaking like that is very common in boosted stuff and it’s always related to cylinder pressure spikes and not enough ring gap.
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