This is the only time in history a torpedo caused a secondary explosion < /Rosie>
Also, the U.S. did not enter the war in 1915, in case anyone forgot. It took the sinking of a DOZEN U.S. ships by the Germans, after repeated promises not to sink neutrals. Any ONE of those should have been grounds for war, and the sickening thing is that Woodrow Wilson waited so long to do what needed to be done in the first place.
The same people who complain about 3,000 civilians being killed at the WTC, which, God knows, must have had SOME offices doing "defense work," hence were "legitimate targets" as the jihadists claim, want to excuse German atrocities at sea. So the question of what the Lusitania was transporting is irrelevant. Even if it was ALL high explosive shells, the U-boats were NOT to be torpedoing passenger liners and they had promised not to do so in any event.