Best way to lower the counter in this NPC cloner script when a child gets removed?

wait(5)
local child = game.workspace.Spawn.ChildAdded:Connect(function(child)
	
end)

local ZombieCount = 0 --Supposed to cap the zombies

local NPC = game.ReplicatedStorage.ZombieStorage.Zombies.Zombie

local spawner = game.workspace.Spawn --The spawning brick

local children = game.workspace.Spawn:GetChildren()

while ZombieCount <5 do
	local Clone = NPC:Clone()
	Clone.Parent = spawner
	Clone.Torso.CFrame = spawner.CFrame --Spawns the zombie where the brick is
		wait(0.05)
	if child then ZombieCount = ZombieCount +1 --Counter that keeps track of zombies
	end
end

--Need a way to lower the count on death

I need this count to lower so another NPC can spawn after one dies, but I haven't figured out how to do it after toiling with the script for a while.

I've tried:

if Clone.ChildRemoved then ZombieCount = ZombieCount -1 --the zombies just infinitely spawn


elseif Clone.ChildRemoved then ZombieCount = Zombiecount -1 --nothing happens when they die

if spawner.ChildRemoved then ZombieCount = Zombiecount -1 -- infinite spawns again

if spawner.ChildRemoved == true then ZombieCount = Zombiecount -1 --nothing happens when they die

if Clone.Humanoid.Died == true then ZombieCount = Zombiecount -1 --nothing happens when they die

Does the while do script just permanently end when they hit the cap? Should I be calling on all of the children? I've looked around and can't figure out what I should be calling/the correct event to call (if there is one).