What sinks a ship after an explosion splits it in half?

What actually sinks a ship when an explosion splits it in half?

Water entering through the enormous breach causes the sinking. The explosion creates damage that the ship cannot contain.

An explosion that splits a ship creates an enormous opening for water to enter. The immediate structural break and the subsequent sinking are connected by that uncontrolled flooding. Fire can also destroy structural integrity until the damaged ship can no longer withstand water pressure. This distinction explains why a weapon's damage matters through its effect on the hull's ability to keep water out.