Does death come all at once?

[Bob May]

When death comes will it be all at once or more of a gradual thing?
I'm not talking about instant death like a car accident or something. But death of natural causes.
Does a person sense it days, months or even years before it arrives? Or is it a suprise?
Is there a difference to the quality of their awareness leading up to that day, that hour?
What do you think?Bob