The Blitz is on

Typically, September 1 has been the first day of school. That's been changed this year in Poland to the 4th. This year the day can stand alone as a remembrance of Germany's invasion of Poland on September 1, 1939. Hitler invaded "without any warning or declaration of war." Two days later, Britain and France declared war on Germany and the world was in for six years of brutal fighting.

Here's the story from the BBC as they remember this day in history:
1939: Germany invades Poland

On the first day, about 200 residents of Poznan were killed from German bombs.

Here's a lengthy article about Poznan in Polish published today. Even if you don't read Polish, you can check out some of the thumbnail-size historic photos from the first days of the war in Poznan.