Blowing up your own ammnition by accident and blaming the Spanish?
ADDENDUM: Clarification for those up|down voting like a yo-yo:
On February 15, 1898, the American battleship Maine exploded while sitting in the Havana harbor, killing two officers and 250 enlisted men.
Fourteen of the injured later died, bringing the death toll to 266.
A naval board of inquiry concluded that the blast was caused by a mine placed outside the ship.
Release of the board’s report led many to accuse Spain of sabotage, helping to build public support for war.
Subsequent studies, including one published in 1976 and later reissued in 1995, determined that the ship was destroyed from the inside, when burning coal in a bunker triggered an explosion in an adjacent space that contained ammunition.
ADDENDUM: Clarification for those up|down voting like a yo-yo:
Law Library of Congress: https://web.archive.org/web/20210424181239/https://www.loc.g...https://en.wikipedia.org/wiki/USS_Maine_(1889)
https://en.wikipedia.org/wiki/Spanish%E2%80%93American_War