After graduation, my friend from college got a job on a barge in the New York harbor. They had just installed a new underwater gas pipeline to Brooklyn, and his barge’s job was to cover the pipeline with sand. The sand they used came from “overseas.” The problem was that they kept finding grenades in the sand. His supervisor told the crew that if they found one more grenade, the whole project would be cancelled. Miraculously, they never found another grenade and completely covered the gas pipeline.