A sharp, sudden turn with reports of a loud bang heard and felt through out the hull tells me they must have grounded on some obstruction and tore open the whole side, flooding the engine room and heeling the ship over. Any cargo shifting would exacerbate the heel but I do not believe any deck cargo containers could be heavy enough to make that much of a heel possible.
I suspect they will find extensive damage once a proper assessment of the hull can be made. It is completely submerged now and I am not sure what position it finally came to rest in. It could be laying over on the damaged side, and with water conditions merely murky on a good day it will be difficult to tell much until they can raise it.
And raise it they will. South Korea has an enormous maritime industry with plenty of heavy lift available that is more than capable of raising a ship this size, intact. It will be interesting to see what condition the hull is in.