The technology and expertise for dismantling manmade structures is available for small and safe structures, such as building a few stories in height, but for many structures being built today the technology for demolishing them does not exist. The tools, such as robots, for dismantling nuclear reactors have to be invented while they are being decommissioned. The techniques for tearing down building like the Sears Tower do not exist. The over 6000 oil drilling platforms used at sea were never design to be dismantled even though a 1958 Geneva convention requires that they have to be removed and the sea returned to its natural state.