 On May 23, 1899, the Spaniards finally evacuated Zamboanga, after burning down most of the city's buildings in contempt of the Zamboangueños' revolt against them.General Álvarez's term was cut short when the commander of Tetuan, Isidro Midel, cooperated with the Americans in exchange for the presidency with his cohort Datu Mandi.He then ordered the assassination of Major Melanio Calixto, acting commander of Zamboanga, because Álvarez was on a trip to Basilan to recruit more forces.