Why couldn't it have been just a heart attack?

Clemenza was overweight -- and besides, does everyone in the mafia need to be whacked? Doesn't anyone die of natural causes?

I know that Frankie Five Angels thought otherwise, but couldn't it have just been his anger at the Rosatto Bros. that was clouding his better judgement? Plus, other than Frankie's line about it "not being a heart attack", Clemenza's death is not mentioned again. If we were supposed to believe it was something else -- wouldn't FFC and Puzo have planted something to confirm our suspicions?

Now, if I were Winegardner, I would have explored the possibility of Clemenza getting knocked off instead of him collapsing on a stove (which I guess was supposed to be some kind of attempt at black comedy fused with irony) but in the films, I like to think that Clemenza was a loyal guy who was able to stay ahead of getting killed my rival mobsters and dying on his own terms, even if it was just a heart attack.

What does everyone else think?

The "that was no heart attack" line has been the subject of many threads here. One view is that Clemenza's possible health problems were aggravated by the problems caused by the Rosatos' feud with Frankie.
If I were Weingartner, I'd never write another word.

I know this has been a much discussed topic on the boards -- but I was taking a kind of different approach saying that it was what it was -- a heart attack. Interesting theory about the Rosatto Bros. dealings having an indirect impact on his condition though...

After hearing Cici say that I figured he would have atleast gone into detail. Something like

Fredo:"Heart attack, huh?"

Cici:"No - No, that was no heart attack."

Fredo:"What do you mean? Everyone around here heard it was a heart attack."

Cici: "______"(real description of Clemenza's death)

Atleast that's how I imagined the convo would have gone had Frankie not started complaining about waiting for an audience with Michael.

that part literally came on just a few seconds ago...cici says that was no heart attack, and frankie 5 angels cuts him directly off adn goes "thats why im here, to talk to mike about this rossatoo brothers buisness"

im guessing from how it went down that they had somethign to do with his death...whether they mean to say that either they killed him, or that clemanza died froma heart attack from all the obvious stress of dealign with them?