Does an apartment breaker box need a main disconnect?

[tonype]

Apartment building with a 100-amp main breaker (old building and undersized).

Dwellings (there are 7) all have 100-amp rated panels, but none have main breakers. These all rely on the main breaker to the building. Also, some of these dwellings have 7 or 8 circuits.

Putting aside that the 100-amp service is inadequate, in theory, do the dwelling panels (which are all separately metered after the main disconnect) require their own separate main disconnects?

 

[kwired]

A little unconventional but is possible to be code compliant. Load calculations will possibly be a big factor in whether this is ok, but if they are pretty small apartments and have gas heat, water heating and range, it has some chance of being ok.