Those are mostly old people. Old people are sustainable to lot of things and when they get sick from anything, they are more likely to die.
Likely don't verify that the flu killed them, more likely they would have died from something but the flu like symptoms is what they had that pushed them over the edge so they say it is the flu.
Judging by the arms on most of them, they might want to lay off the beer.
>industrialized genocide
Kek, the Germans were masters of engineering but decided forcing 100s of people into a room with one door, gassing them, then hauling back out the same door, put them on an elevator, and them burning the bodies in ovens was efficient. Factory planning at its best.