The Maine could be described as an armored cruiser or 2nd class battleship & was sent to Havana Harbor to protect US interests during the Cuban War of Independence. "Remember the Maine & to hell with Spain" was said & remembered when it exploded & sank in February of 1898. 268 sailors ( ¾ of her crew) were killed. The Navy board of inquiry ruled that it was sunk by an external explosion from a mine, but some US Navy officers disagreed, suggesting that the ship's magazines were ignited by spontaneous fire in a coal bunker. The Maine used bituminous coal known for releasing “firedamp”. This mixture of gases (composed mostly of flammable methane) was known to be prone to spontaneous explosions.