Pearl Harbor: Who Fired First?

On the morning of 26 November 1941, a Japanese navy squadron left its rendezvous near the Kuril Islands en route to the Hawaiian Islands. Admiral Isoroku Yamamoto, the commander of the imperial Japanese fleet, hoped to demoralise the United States by means of a crushing pre-emptive strike on the US fleet at Pearl Harbor and win the resulting war within six months. More than 60 years later, marine biologists and engineers diving off the island of Oahu make a startling discovery 360 metres below the surface. They find a midget submarine which was part of the Japanese plan to destroy Pearl Harbor, but is this the craft fired upon by the destroyer USS Ward on 7 December, an hour before the infamous Japanese attack?