The Lusitania was a ship flagged by a belligerent, carrying contraband, and in a designated war zone. No sympathy for any American stupid enough to sail on it despite clear warnings from the Kaiser. There was nothing that the US would have been authorized in avenging.
The ship carried artillery fuses, guncotton, shrapnel for artillery shells, shells for 13 pound artillery, ready to fire but for the fuse. It is not clear whether the artillery shells and fuses caused the secondary explosion, and thus the sinking. (Official reports claim the shells and fuses were stored separately, which wasn't the usual practice).
Thanks for sticking up for the Second Reich.
This is not Stormfront, you know.