How come when i tp the HumanoidRootPart, my character dies? (NOTE ITS A STARTERCHARACTER)

local StartRemote = game:GetService("ReplicatedStorage"):WaitForChild("Remotes").StartGame
local TeleportPos =  Vector3.new(1.5, 33.5, 123.5)
StartRemote.OnServerEvent:Connect(function()
	local Players = game.Players:GetChildren()
	local Impersonator = Players[math.random(1,#Players)]
	for i = 1,#Players do
		local Who = Instance.new("StringValue",Players[i])
		Who.Name = "Who"
		Players[i].Character.HumanoidRootPart.Position = TeleportPos
		Players[i].PlayerGui.LobyGui.Enabled = false
		Players[i].PlayerGui.GameGui.Enabled = true
		local Frame = Instance.new("Frame",Players[i].PlayerGui.GameGui)
		Frame.Position = UDim2.new(0,0,-0.1,0)
		Frame.Size = UDim2.new(1.1,0,1.1,0)
		Frame.BackgroundColor3 = Color3.fromRGB(0,0,0)
		local Role = Instance.new("ImageLabel",Frame)
		Role.Size = UDim2.new(0.9,0,0.9,0)
		Role.BackgroundTransparency = 1

		if Players[i] == Impersonator then
			Role.Image = "https://www.roblox.com/asset/?id=85390964"
			Who.Value = "Impersonator"
		else
			Role.Image = "https://www.roblox.com/asset/?id=422422247"
			Who.Value = "Investigator"
		end

		--game.Debris:AddItem(Frame,5)
	end
end)