You would think that for a ship so expensive they would have had a little redundancy in the ship systems.
The cost for lack of it will be very high.
It’s going to cost Carnival a bundle.
The last cruise we were on, the celebrity solstice, bragged about having two engine rooms well separated from each other, and being able to run the ship with one room completely out of commission. I think they called it their “return to port” capability, even in case of major fire.
One of these boats will usually have 2-4 main engines, and smaller ones for emergency power or hotel loads.