Imagine boarding a giant ship for a trip across the ocean. That is what 1,959 people did in May 1915. They boarded the Lusitania in New York City. The ship was heading to England. World War I was raging in Europe. Germany had warned that ships entering the war zone could be attacked. Most passengers felt safe on such a large vessel. On May 7, a German submarine spotted the Lusitania off the coast of Ireland. The submarine fired one torpedo. It struck the ship on the right side. A second explosion followed almost immediately. The Lusitania sank in just eighteen minutes. About 1,198 people died, including 128 Americans. The sinking caused outrage in the United States. Many Americans demanded action. President Woodrow Wilson sent angry diplomatic messages to Germany. Germany agreed to stop attacking passenger ships for a time. But the damage was done. American opinion had shifted against Germany. Two years later, the United States entered World War I.