How come my character dies when given a new torso?

So last time I asked how to morph a character and I did find an answer. It worked, however I wanted to try and use welding. I managed to remove the character's right and left leg and replaced it with my custom morph's legs. I moved on to the torso and when I made it uncollidable and transparent and replaced it with my custom morph's torso, it killed my player when I tested it. I then tried to remove the torso and quickly replace it but that did not work either. I disabled the script and looked into my player's torso, thinking that the Motor6D were the problem and I was right. So now I'm thinking about how to successfully remove the torso or make it invisible and replace it with my own. Here's the script.

game.Players.PlayerAdded:connect(function(plr)
	plr.CharacterAdded:connect(function(char)
		wait()
		--Works here
		local newleftknee = game.ServerStorage.CustomModel.LeftKnee:Clone()
		newleftknee.Parent = char
		local weld = Instance.new("Weld", newleftknee)
		weld.Part0 = newleftknee
		weld.Part1 = char.Torso
		weld.C0 = CFrame.new(0.5, 1.5, 0)
		char["Left Leg"]:Destroy()
		newleftknee.Anchored = false
		
		local newleftleg = game.ServerStorage.CustomModel.LeftLeg:Clone()
		newleftleg.Parent = char
		local weld1 = Instance.new("Weld", newleftleg)
		weld1.Part0 = newleftleg
		weld1.Part1 = char.Torso
		weld1.C0 = CFrame.new(0.5, 3, 0)
		newleftleg.Anchored = false
		
		local newrightknee = game.ServerStorage.CustomModel.RightKnee:Clone()
		newrightknee.Parent = char
		local weld2 = Instance.new("Weld", newrightknee)
		weld2.Part0 = newrightknee
		weld2.Part1 = char.Torso
		weld2.C0 = CFrame.new(-0.5, 1.5, 0)
		char["Right Leg"]:Destroy()
		newrightknee.Anchored = false
		
		local newrightleg = game.ServerStorage.CustomModel.RightLeg:Clone()
		newrightleg.Parent = char
		local weld3 = Instance.new("Weld", newrightleg)
		weld3.Part0 = newrightleg
		weld3.Part1 = char.Torso
		weld3.C0 = CFrame.new(-0.5, 3, 0)
		newrightleg.Anchored = false
		
		--Problem starts here
		local newtorso = game.ServerStorage.CustomModel.Torso:Clone()
		newtorso.Parent = char
		newtorso.CanCollide = false
		local weld4 = Instance.new("Weld", newtorso)
		weld4.Part0 = newtorso
		weld4.Part1 = char.Head
		weld4.C0 = CFrame.new(0, 1, 0)
		char.Torso:Destroy()
	end)
end)