For those of you interested in 02 September: This is what I found. (I'll admit it, I love doing research

Source:
http://www.nationmaster.com/encyclopedia/Zeppelin"The first night-fighter victory came on September 2, 1916 when W. Leefe-Robinson shot down one of a sixteen strong raiding force over London. He won the Victoria Cross."
Source:
http://www.firstworldwar.com/airwar/bombers_zeppelins.htm"William Leefe-Robinson, flying a BE2c, was the first to shoot down a dirigible over Britain, on the 2nd of September, 1916. The massive fire of the burning airship was visible for over a hundred miles. This was during a raid of twelve naval airships which were, somewhat unusually, accompanied by four army airships. Leefe-Robinson became an instant hero. He survived the war, only to die a month later in the influenza epidemic."
Note that they mention the influenza epidemic. I think this is the "plague" refered to in FMA.
http://www.firstworldwar.com/atoz/influenza.htm"In the summer of 1918 a severe form of influenza - 'Spanish Flu' or 'La Grippe' - broke out which eventually claimed up to 70 million lives around the world until it finally, unexpectedly, disappeared in 1919. In this the virus claimed far more lives than the war itself."
My personal (crazy?) theory is that the next episode will have a flashback in it featuring Hohenheim during the first world war (before the epidemic and so before he created the philosopher's stone). During this time he had a kid (Envy) whom we see in the preview.
Edit: Wait! I just realized something. Hohenheim switched bodies when he created the philosopher's stone, so my theory is flawed... Oh well... Try and try again