Terrain is locked, could I use a script to permanantly remove it?

So for some reason when I try to delete this water terrain, I get an error and it won't delete.

error

The Parent property of Workspace.Terrain is locked, current parent: Workspace, new parent NULL

I get this error whenever I try to delete it. I went in to properties and tried to untick "Locked" but it wouldn't let me.

Now I'm thinking the only option I have is to some how remove it with a script.

something like this?

for _, v in pairs(game.Workspace) do
    if v ~= nil  and v.Name = "Terrain" then
        v.Destroy()
end

Something among those lines. I really have no idea what else I can do so here's hoping. So how can I get a script to delete something out of the workspace forever?

Is there a way this can be done without scripting?