The Sinking of the Maine

On February 15, 1898 the American battleship the USS Maine exploded, killing 266 people on the ship. No one knows what caused the explosion but many suspect it was the Spanish while others think that the explosion was an accident that happened inside the ship. It is unlikely that the Spanish would've  wanted to make enemies with the U.S. but with America supporting the revolution in Cuba it is possible  could have placed a mine where it would explode and hit the maine. However investigations later on revealed that a mine or torpedo wouldn't be enough to explode the magazines in the ship. The explosion would have to have been an internal explosion. The question is weather or not it was an accident or it was sabotaged. Even today with such little evidence on what happened there is know way to know for sure what caused the explosion.

Sources:
http://www.spanamwar.com/Mainemo1.htm
The American Vision (pg. 308-309)