What is wrong with my disaster script?

I tried editing this disaster script to make the disaster end when everyone dies, but it doesn't work. Help?

Script:

disasters = {"ogm"} -- This is where you list the names models that you want to use for disasters.
-- Disaster names are case-sensitive and all disaster models must be in the lighting

countdownTime = 125 -- The ammount of time to wait between each disaster.
disasterTime = 40 -- The ammount of time that the disaster will be in the game before it is removed.

countdownMessage = "The next disaster will occur in %s seconds." -- The message displayed between disasters. %s will be replaced with the number of seconds left.
disasterMessage = "The Disaster Is: %s" -- The message displayed when a disaster occurs. %s will be replaced with the disaster name. Set to nil if you do not want a message

-- Unless you know what you are doing, please leave the below code alone.
items = {}
leaderboard = game.Workspace:findFirstChild("BTS Leaderboard") -- Used to work with my BTS leaderboard
local w = game.Workspace:getChildren()
for i=1,#w do
	if w[i].Name == "leaderboard" and w[i]:findFirstChild("running") ~= nil and w[i]:findFirstChild("points") ~= ni then
		leaderboard = w[i]
	end
end
for i=1,#disasters do
	local item = game.Lighting:findFirstChild(disasters[i])
	if item ~= nil then
		item.Parent = nil
		table.insert(items, item)
	else
		print("Error! ", disasters[i], " was not found!")
	end
end

function chooseDisaster()
	return items[math.random(#items)]
end

function sethint(text)
	local hint = game.Workspace:findFirstChild("hint")
	if (hint ~= nil) then
		hint.Text = text
	else
		print("Hint does not exist, creating...")
		h = Instance.new("Hint")
		h.Name = "hint"
		h.Text = text
		h.Parent = game.Workspace
	end
	--print("Hint set to: ", text)
end

function removeHint()
	hint = game.Workspace:findFirstChild("hint")
	if (hint ~= nil) then hint:remove() end
end

function countdown(time)
	sethint(string.format(countdownMessage, tostring(time)))
	while (time > 0) do
		wait(1)
		time = time - 1
		sethint(string.format(countdownMessage, tostring(time)))
	end
	removeHint()
	return true
end

while true do
	countdown(countdownTime)

	if leaderboard ~= nil and leaderboard:findFirstChild("running") and leaderboard:findFirstChild("points") then -- For use with my BTS leaderboard.
		leaderboard.points.Value = 30
		leaderboard.running.Value = true
	end

	local m = chooseDisaster():clone()

	if disasterMessage ~= nil then
		local msg = Instance.new("Message")
		msg.Name = "DisasterMsg"
		msg.Text = string.format(disasterMessage, m.Name)
		msg.Parent = game.Workspace
		wait(3)
		msg.Parent = nil
	end

	m.Parent = game.Workspace
	m:makeJoints()
	wait(disasterTime)
	m:remove()
	
else
	
	for _,v in pairs(game.Players:GetChildren()) do -- everything in players
if v.Character ~= nil then -- if the person exists
v.Character:BreakJoints -- kills
end end -- ends function


	if leaderboard ~= nil then -- For use with the bts leaderboard.
		leaderboard.running.Value = false
	end
end

Use a table to store who's dead. Which is updated after a Died event is fired. Like so:

deadPlayers = {}
function checkDeadPlayers() 
	if(#deadPlayers == game.Players.NumPlayers) then
		-- Stop disaster
        deadPlayers = {}
	end
end
game.Players.PlayerAdded:connect(function(player)
	player.CharacterAdded:connect(function(character)
		character.Humanoid.Died:connect(function()
			if(player not in deadPlayers) then
				table.insert(deadPlayers, player)
				checkDeadPlayers()
			end
		end)
	end)
end)