Other hostile Indians attacked San Luis Obispo on three separate occasions before 1774. During the attack, the thatched roofs of the mission buildings were set afire by blazing arrows. In May 1807, the mission was designated as one of six in which the California priests could make their annual retreats for spiritual exercises. Following Mexico's war against Spain in 1810, all the California missions were forced to contribute food and clothing to the army. In 1830, the bell tower was destroyed in an earthquake, but was later rebuilt with stone.