The sinking of the Lusitania, 1915
One of the most terrifying weapons of World War I was the U-Boat. With one of these U-Boats by a torpedo, a civilian passenger liner, the Lusitania was fired on 7th May, 1915 by the Germans.
It sunk off the coast of Ireland and killed more than 1.200 people, including 128 Americans. This devastating event pushed America closer to joining the war.