Which of these events triggered the Spanish American war?

1) The explosion of USS Maine, a United States battleship, which was located in the Havana Harbor at that time. It was assumed that the Spanish were responsible for that tragedy.

2) The exposistion of the Delome Letter. It was a letter from Spain addressed to the Spanish Cuban government. It was intercepted by the Cuban revolutionaries and was printed for public distribution. The letter contains negative statements about the American President McKinley.

These two events on top of other Cuban incidents, which garnered the sympathy of the United States to the Cubans, triggered the Spanish-American War.