Why does my fall damage script kill you when the character is in a negative Y value?

I know I'm bad at phrasing titles, but my point is that whenever the character is in a Y-axis of (0,-1,0) and below, it just automatically dies. I do not know at all why! Also, in some general cases, the character just dies for unkown reasons because of fall damage. If you can help me improve this script or create an entirely new one, it would be a great help. (This was taken from free models and edited from me so I could learn)

wait(5)

bin = script.Parent
probability = math.random(-2, 10)
humanoid = bin:FindFirstChild("Humanoid")
ll = bin:FindFirstChild("Left Leg")
rl = bin:FindFirstChild("Right Leg")
la = bin:FindFirstChild("Left Arm")
ra = bin:FindFirstChild("Right Arm")
h = bin:FindFirstChild("Head")
freefall = false
startingHeight = 0
endingHeight = 0
ll.Elasticity = 0
rl.Elasticity = 0
la.Elasticity = 0
ra.Elasticity = 0
h.Elasticity = 0
bin.Torso.Elasticity = 0

function onFreeFall()
	freefall = true
	wait(.25)
	startingHeight = bin.Torso.Position.y
end

function onTouched(part) --The ground has been touched.
	if freefall == true and bin:findFirstChild("Parachute") == nil and humanoid.Health > 0 and part.CanCollide == true then 
		
		endingHeight = bin.Torso.Position.y
		local averageHeight =  startingHeight - endingHeight
		if averageHeight > 25 then
			if bin:FindFirstChild("Torso") and bin.Torso:FindFirstChild("Crunch") then
				bin.Torso.Crunch:Play()
			end
			humanoid.Health = humanoid.Health - ((averageHeight * 0.1)^2)
			startingHeight = 0
		end
	end
end


humanoid.FreeFalling:connect(onFreeFall)
ll.Touched:connect(onTouched)
rl.Touched:connect(onTouched)
la.Touched:connect(onTouched)
ra.Touched:connect(onTouched)
h.Touched:connect(onTouched)

Try using this in a script in ServerStorage. If that does not work, tell me the errors.

Don't forget to accept this answer if it helped!

EDIT: I made a mistake. I put :GetAllChildren() instead of :GetChildren()

R6:

wait(1)
local MaxVelocity = 15
local DMGperVelocity = 3
game.Players.PlayerAdded:connect(function(plr)
	local FreeFall = false
	plr.Character.Humanoid.FreeFalling:connect(function()
		FreeFall = true
	end)
	plr.Character:GetChildren().Touched:connect(function()
		if plr.Character.Velocity >= MaxVelocity then
			plr.Character.Humanoid.Health =  plr.Character.Humanoid.Health - (plr.Character.Torso.Velocity * DMGperVelocity) 
		end
	end)
end)

R15:

wait(1)
local MaxVelocity = 15
local DMGperVelocity = 3
game.Players.PlayerAdded:connect(function(plr)
	local FreeFall = false
	plr.Character.Humanoid.FreeFalling:connect(function()
		FreeFall = true
	end)
	plr.Character:GetChildren().Touched:connect(function()
		if plr.Character.Velocity >= MaxVelocity then
			plr.Character.Humanoid.Health =  plr.Character.Humanoid.Health - (plr.Character.UpperTorso.Velocity * DMGperVelocity) 
		end
	end)
end)