[Sethomas]

I believe you're thinking of the USS Maine, an ironclad that exploded from a fuel malfunction off the coast of Havana. That ended up triggering the Spanish-American War, hence "Remember the Maine, Hell to Spain". As for the Lusitania, I don't think there's any good reason to believe that it wasn't a German submarine sinking it with a German torpedo, but the issue lies in the British violating war agreements about what is acceptable as a civilian boat and where they were safe to sail. The British willfully sailed the Lusitania through hot waters, and the Germans were led to believe (correctly, I think) that the ship had a sizable cache of arms along with its passengers, thus disqualifying it from immunity anyways.

It also wouldn't surprise me if the Zimmerman message was a British hoax, but I'm not convinced either way.