War was declared by the United Kingdom against Germany on September 3, 1939, and the Battle of the Atlantic would began the same day. One week later Canada followed the United Kingdom and declared war against Germany. This dangerous threat from the U boats began on September 3, 1939 with the sinking of the SS Athenia from the torpedoes of a German U Boat. The Athenia had approximately 1,400 passengers and crew onboard and the death toll was 117 passengers and crew. There were American citizens on board at the time of the sinking.