Investigators have found the culprit behind a $10 million nuclear submarine accident: Tracing paper. HMS Trafalgar struck the seabed in 2002 because a piece of tracing paper obscured key details on a nautical chart, the Guardian reports.
The Trafalgar struck bottom during a training exercise, with unsupervised students involved in navigation. Tracing paper had been thrown over the navigation chart to protect it. One crew member actually noticed the problem, but too late to prevent the pricey mishap.