Why is this NPC dying when I command it to move to a certain location?

This code clones an NPC from Lighting and drops it into the Workspace so it can be moved, however it dies immediately.

az = game.Lighting.WalkOut:Clone()
az.Parent = game.Workspace
game.Workspace.WalkOut.PrimaryPart = game.Workspace.WalkOut.Torso
for gha = 156, 143, -1 do
	wait()
	game.Workspace.WalkOut:MoveTo(Vector3.new(gha, 4, -1))
end
for ghb = -1, 4, 1 do
	wait()
	game.Workspace.WalkOut:MoveTo(Vector3.new(143, 4, ghb))
end