Bruno and Philip Tattaglia.

Interesting: Who dies by natural causes?

- Vito
- Michael
- Signora Corleone
- Genco
- Tom(?)

Which reminds me a little of the fate of the Russian revolutionary:
Lenin just as Vito got very sick after being shot by an assassin, still he held some strings.
One by one all the others were killed by Stalin (=Michael).
We don't know what happened to Tom, but he may have shared Trotsky's fate.
In the end Stalin/Michael dies alone. Only his bulldog Beria/Neri survived.
Stalin/Michael was careless about his kids, so they died.

I know, I stretched it a little, but I time and again I find parallels between Stalin & Michael.