On November 3, 1938, before the US entered WWII, the German-flagged steamship Vancouver was in SF Bay to pick up cargo and passengers. As it was leaving port, an explosion near the engine room blew a large hole in the side and the ship sank in the estuary. It was immediately labeled suspicious, and authorities began an investigation. This made front page news in the Oakland Tribune, and was covered by newspapers all over the world. So it’s not surprising that Herman headed over to the Oakland estuary the next day to take some movies. Read more about the mysterious explosion on the Oakland Wiki here.