In ALS and other degenerative neuromuscular disorders one loses the ability to swallow effectively and protect against aspiration along with the inability to speak. People affected by this, like my grandfather, will usually require a feeding tube to allow enough calories without risking aspiration. However, even with this, we are constantly relying on our epligottis and swallowing reflexes to prevent microaspirations of saliva and oral bacteria. Because of this, people with ALS are at extremely high risk for pneumonia, which would be my first guess as being most likely. His was lucky in that his ALS was a subtype that didn't progress as rapidly as most do.

I think you don't deserve the downvoting you are getting even though the timing of your question is not great, you're still trying to understand what the natural progression of ALS is.

At 76, I think it's fair to say he just died.

I actually had no idea he was that old. Maybe he looked younger than he was because he had no wrinkles.

Nobody "just dies". Most "natural deaths" are still heart failure. The rest are other kinds of organ failure.

For a lot of people that die natural deaths they could have lived longer if they had kept fit. It just gets really hard to either do or justify when everything hurts and gets harder to do year over year. Or when you are confined to a wheelchair since your early 20s, were told you would only live two years, and then beat that prognosis 27 times over.

But if you are able, even small amounts of cardio exercise could dramatically extend your health and lifespans in old age.

It's true that an autopsy will show a cause of death for anyone. In that sense, you don't "just die".

But after a certain point, that cause of death starts looking pretty meaningless. Everything is failing at once; if you hadn't died of your actual cause of death, you would have died shortly afterwards from another one. In that sense, you do "just die" of old age.

In the UK, old age isn't a legal cause of death for people under 80.

It's called being colloquial, jeez

Yes, and given his adulthood-long health problems, it's a bit of a miracle he lived as long as he did. Amazing man.

I'm sure we'll find out more in due course. Right now, it's 4am and all we have is a statement from the family. I'm sure they have much better things to be doing right now.

That said, his original prognosis was that he wouldn't reach his 25th birthday, so he hasn't really done too bad.

Like black holes, very little information ever escapes death.