Popé then ordered the revolt to begin a day early. The Hopi pueblos located on the remote Hopi Mesas of Arizona did not receive the advanced notice for the beginning of the revolt and followed the schedule for the revolt. On August 10, the Puebloans rose up, stole the Spaniards' horses to prevent them from fleeing, sealed off roads leading to Santa Fe, and pillaged Spanish settlements. A total of 400 people were killed, including men, women, children, and 21 of the 33 Franciscan missionaries in New Mexico. Survivors fled to Santa Fe and Isleta Pueblo, 10 miles south of Albuquerque and one of the Pueblos that did not participate in the rebellion. By August 13, all the Spanish settlements in New Mexico had been destroyed and Santa Fe was besieged. The Puebloans surrounded the city and cut off its water supply. In desperation, on August 21, New Mexico Governor Antonio de Otermín, barricaded in the Palace of the Governors, sallied outside the palace with all of his available men and forced the Puebloans to retreat with heavy losses. He then led the Spaniards out of the city and retreated southward along the Rio Grande, headed for El Paso del Norte. The Puebloans shadowed the Spaniards but did not attack. The Spaniards who had taken refuge in Isleta had also retreated southward on August 15, and on September 6 the two groups of survivors, numbering 1,946, met at Socorro. About 500 of the survivors were Indian slaves. They were escorted to El Paso by a Spanish supply train. The Puebloans did not block their passage out of New Mexico.
Question: Whose riding animals were stolen?
Answer: the Spaniards