Depends on the system. Local rules and how the transformers are set up.
Gensets last is not an intentional punishment just a precaution.
Each transformer is protected by a 1 or 1/2 amp fuse.
Those are the fuse holders by the can.
Some times all are pulled on a trouble street.
Just a side note. Think how long it would take to make all the connections in the pic.
With big gloves and a high voltage coat etc.
When a generator is known or heard they pull that fuse.
After the whole line is repaired often they go down and reset fuses one at a time.
So as to not overload feeder circuit.
A house with lights on will get passed as some one may think the fuse was set.
Some times we forget the house with lights on by mistake.