Why doesnt it change my CameraMode when this local script runs?

Hi. so when you press a button, it makes your camera first person. That works. But, this local script is supposed to make it so it undos that. it doesnt work, though. its in StarterGui.

game.Players.PlayerAdded:Connect(function()
    local plr = game.Players.LocalPlayer
    plr.CharacterAdded:Connect(function(character)
        local hum = character:WaitForChild("Humanoid")
        hum.Died:Connect(function()
            plr.CameraMode = Enum.CameraMode.Classic
        end)
    end)
end)