Passengers describe 'sewage running down the walls' and people acting like 'savages'

[HooptieWagon]

100. The toilets probably are electric flush.

Even yachts down to about 35 feet have electric heads now.
And just a guess, but I imagine the controls for the main engines are electrically controlled, if you can't operate the gearshifts, throttles, steering, and propellor pitch controls, the engines are useless. Its also possible there are fuel transfer pumps, from the main tanks to day tanks, that are now inoperable. I suspect the anti-roll stabilizers are nonfunctioning as well, although the ship has to be making at least moderate speed for them to work. Since the ship appears to have communication, it probably has some navigation functions too...but they don't draw much power...there may be a small generator for that, or they mave be preserving battery power to keep those systems going.