I think that death is a pure spiritual experience. you are seperated from the physical (your body) and you are returning to your first created form- the initial spirit that was created by the creator. so death is returning to the initial spiritual creation
I see it like getting out of a car, in line with the teachings in the Tibetan Book of the Dead, with the idea that we incarnate into a “nested set” of bodies of you will. 
We never left any spiritual existence behind, we just stepping into this dense one in addition, just for a while.
I think it’s both physical and a spirit thing. I can’t comment on the spirit aspect as I do not yet remember any past lives. The physical however, I definite as the absence of heartbeat (I don’t count brain death because it’s obvious the brains not dead if it’s still instructing the heart to pump and or lungs to breathe I won’t expound further lest I trespass into forbidden realms involving the politics of organ donation).
I think the moment of dying will be the most physical one has ever felt.
After that the spiritual aspect will take over but Id say if you expect to not feel anything physical in that moment youre expecting wrong.