from archaeology.org: The nearly century-old debate about whether the passenger liner Lusitania was transporting British war munitions when torpedoed by a German U-boat is over. Physical evidence of just such a cargo has been recovered from the wreck, which rests 12 miles off the Irish coast in 300 feet of murky, turbulent water.
Lusitania was sunk off County Cork on May 7, 1915. The attack killed 1,198 people, including 128 Americans, and helped push the United States into World War I. Ever since the ship went down, there have been suspicions that Lusitania was carrying live munitions. Under the rules of war, that would have made the liner a legitimate target, as the Germans maintained at the time.
The British government has always been evasive about the presence of munitions on Lusitania. Two cargo manifests were submitted; the second, filed after the ship sailed, indicated there were light munitions on board. Some believe the ship was carrying much more, however, and that the British Navy attempted to destroy the wreck in the 1950s to conceal its military cargo.