I've been looking everywhere on the internet for an answer to this but it seems nobody has even asked the question from what I can find.
In D&D 5e, I want to know if one can kill the physical body of a creature who has used a spell like Astral Projection. All the questions about this spell that I've seen on this site and others only seem to address whether and how to kill the astral version of the creature, not the physical one. I want to address the latter.
From this link discussing Sequester, it seems obvious that taking damage ends the suspended animation effect. So, what about Astral Projection? Would attacking the body kill the astral version as well? Would taking damage automatically bring the astral version back to the physical body?
To put it another way: Let's say you project yourself to the Astral Plane to hide from a group of creatures that are hunting you on the Material Plane. However, they eventually find your body, which is just lying there in suspended animation. Lacking the ability to Dispel Magic, they simply try to attack your physical body. Can they just go to town attacking your body and eventually kill you, or is your body immune to damage while under the effects of the spell (thus making Astral Projection function much differently from Sequester, despite the fact that they are both called "suspended animation" effects)?
The PHB (p. 215) gives no indication of whether this would be possible. It mentions that
The material body you leave behind is unconscious and in a state of suspended animation; it doesn’t need food or air and doesn’t age.
But this does not deal with effects that would damage or destroy the body from the outside, or other harmful spells or effects besides Dispel Magic. It also mentions that
Your astral form is a separate incarnation. Any damage or other effects that apply to it have no effect on your physical body, nor do they persist when you return to it.
but it does NOT state whether or not the reverse is also true.
My own interpretation is that there seems to be nothing special about this spell that would prevent the destruction of the body. If that is the case, the spell is only as good as the body is safe from attack. (As an aside, I assume then that the destruction of the body would also end the spell in that the connection between body and astral self would be severed. Would it therefore trap the soul in the Astral Plane without a way to return to a body on the Material Plane? Or would the soul cease to exist without the body?)
Thank you for consideration and I look forward to receiving some thoughts on the matter.