Four year old is suddenly having intense anxiety about death. I don't know how to respond.

My son recently began having intense anxiety about dying. We don't have anyone close to us who has died or pets or anything, though we have explained it a little bit to him when his friend's pet died that it's a different part of our life cycle that lasts forever.I think it's possible that it's due to our current pandemic, we have tried to explain to him in age appropriate way what's going on (there's a virus going around which is making people sick so to keep ourselves healthy we have to practice social distancing and make sure to wash our hands regularly and not touch our faces).But recently, suddenly he will become inconsolable crying "I don't ever want to die! Never!" it comes on suddenly and he becomes immediately hysterical.I have been holding him and telling him he is safe and healthy and has nothing to worry about right now, and it seems to help him calm down, but I'm wondering if I should be doing more or doing something differently... I just don't know what to do for him. via /r/Parenting https://ift.tt/2VXggoy