The American press blamed the explosion on the Spaniards because they wanted an excuse for the US to go to war with Spain. The American government knew perfectly well there was no evidence of foul play, but succumbed to public pressure, more out of lazyness than malice. The Spaniards blamed the Cubans for trying to bring the US into the war. The Cubans, who wanted US intervention, blamed the Spaniards. After the war ended, the Cubans blamed the Americans for manufacturing an excuse (by killing their own sailors) to go to war with Spain. That's the story I heard from my family.

What probably happened was an accidental coal dust explosion in the ship's fuel bunkers or fire rooms, an incident that was extremely common in industrial boilers and coal mines in those days. At certain concentrations, floating coal dust in confined spaces can explode due to a stray spark or a sailor lighting his pipe. Grain silos also blow up unexpectedly for the same reason.

No one knows exactly who was responsible for the loss of the Maine, but in the end it probably doesn't really matter.