Teleport Player From Void To Spawn

//ads -- adsterra.com -- native banner
?>
I'm working on a Sky PvP server using only command blocks! If a player dies to another player I want them to drop their items on death, but when they fall down from island, I want to keep their inventory. How can i do this using command blocks?
Pictures about "Teleport Player From Void To Spawn"



Teleporting Players Into the Void For Revenge
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Andrea Piacquadio, Monstera, Oliver Sjöström, Andrea Piacquadio