How to expload terrain when a part touches it?

So I am trying to make a deadly Leaser Beam that destroys everything in its way though I am having a issue with terrain because when you try to set its parent it errors. My issue is that when the Laser Beam hits the terrain a explosion never spawns, and I am sure of that as I tested that when the Laser Beam hits the Terrain it never prints anything if I add a print. Also occasionally for some reason it says it cannot change Terrain's parent even though I have a filter so it will never change Terrain's parent, my Theory behind that is its just too much lag. Here is my script:

script.Parent.Activated:Connect(function()
    if script.Parent.Parent.Name ~= "Gooncreeper" then
                script.Parent:Destroy()
    elseif script.Parent.Parent.Parent.Name ~= "Gooncreeper" and script.Parent.Parent.Name == "Backpack" then
        script.Parent:Destroy()
    end
    ToolLocation = script.Parent
    script.Parent = game.Lighting
    ToolLocation:Destroy()
    game.Lighting.DEATHBEAM.Parent = game.Workspace
    Message = Instance.new("Message", game.Workspace)
    for i = 1, 10 do
        Message.Text = "World Destruction In: ".. 10 - i
        wait(1.5)
    end
    PartLength = 0
    Message:Destroy()
    repeat
        game.Workspace.DEATHBEAM.BEAM.Size = game.Workspace.DEATHBEAM.BEAM.Size + Vector3.new(5,0,0)
        PartLength = PartLength + 5
        game.Workspace.DEATHBEAM.BEAM.Position = game.Workspace.DEATHBEAM.BEAM.Position + Vector3.new(-2.5,-2.25,0)
        wait(0.01)
        PartsTouchingBeam = game.Workspace.DEATHBEAM.BEAM:GetTouchingParts()
        for i, v in pairs(PartsTouchingBeam) do
            if PartsTouchingBeam[i] ~= game.Workspace.DEATHBEAM.Part then
                if PartsTouchingBeam[i].Name ~= workspace.Terrain then
                    PartsTouchingBeam[i]:Destroy()
                else
                    ExplodeTerrain = Instance.new("Explosion")
                    ExplodeTerrain.Position = PartsTouchingBeam[i].Position
                    ExplodeTerrain.Visible = false
                    ExplodeTerrain.Parent = game.Workspace
                    ExplodeTerrain:Destroy()
                end
            end
        end
    until PartLength == 10000
end)