An Indian Navy helicopter flies over the naval dockyard in Mumbai August 14, 2013. Eighteen Indian sailors were trapped and some were killed after an explosion and fire on the diesel-powered submarine INS Sindhurakshak berthed at a base in Mumbai on Wednesday, souring a week of naval milestones, including the launch of a locally built aircraft carrier. REUTERS/Danish Siddiqui (INDIA - Tags: DISASTER MILITARY)