The Maine - cause of the explosion

http://en.wikipedia.org/wiki/USS_Maine_%28ACR-1%29

http://www.history.navy.mil/faqs/faq71-1.htm

http://historymatters.gmu.edu/d/5470/

http://www.arlingtoncemetery.net/ussmaine.htm

On the first issue, the cause of the MAINE's explosion will probably never be known. The widely held "coal bunker fire" theory has some problems that may nullify it. The possibility of a mine, albeit a small mine that was probably not intended to sink the vessel but only create an incident, is still viable. Both theories have been tested using modern computerized explosion modeling techniques and have been shown to be capable of causing the damage found. Of course, neither possibility implicates Spain.

http://www.spanamwar.com/Americanview.htm