How do I create a brick where if the player is in, they will slowly take damage?

So I was thinking to have a wall closing in so that my round does not go on forever. When the player is in that wall, they will take damage. How do I do that? I've tried something but the player remains unharmed while inside the zone, only taking damage upon entry.

Hope this helps

function onTouched(hit)
	if hit.Parent:findFirstChild("Humanoid") then
		while true do
			hit.Parent.Humanoid:TakeDamage(1)
			wait()
		end	
	end
end

script.Parent.Touched:connect(onTouched)