When the United States Navy sent director John Ford to Midway Island in 1942, he believed that the military wanted him to make a documentary on life at a small, isolated military base, and filmed casual footage of the sailors and Marines there working and having fun. Two days before the battle, he learned that the Japanese planned to attack the base and that it was preparing to defend itself. Ford's handheld, 16mm footage of the battle was captured totally impromptu. He had been in transit on the island, roused from his bunk by the sounds of the battle, and started filming. Ford was wounded by enemy fire while filming the battle.

Source: Wikipedia