large haciendas. Between 1680 and 1740 there are indications that the port was used for contraband trade; that is, for trade of arriving Asian products between New Spain and Peru, an interregional trade which had been forbidden. In the second half of the 16th century, the original Spanish shipyards at Zacatula burned. Unable to reconstruct them, new ones were built at Zihuatanejo. The surrounding haciendas occasionally used the bay as a port to ship wood and minerals. The bay was visited during the colonial period by many pirates. Independence and post-colonial era The municipality was spared involvement in the Mexican War of Independence, except for its use by José María Morelos y Pavón as a logistic port in 1811. Morelos created the province of Tecpan, which included Zihuatanejo. However, the municipality did suffer consequences during the Mexican Revolution. Generally, it was sympathetic to the rebel cause and many joined, such as brothers Alfredo, Leonel, Hector, and Homero Lopez. Because of its sympathies, various bands associated with the different forces fighting against the Porfirio Diaz government (and each other) came through here, as well as federal forces. These led to a certain amount of sacking, pillaging, and vandalism. In 1823, with the first republic, Zihuatanejo was separated from Tecpan and became part of the district of Acapulco. When the state of Guerrero was created, Zihuatanejo was part of the municipality of La Unión and Petatlán. 20th century In 1926, a group called the "vidalistas" attacked the town which led to a secret agreement with the government to free a number of the compatriots. In 1952, there was a strike by workers on coconut plantations from Acapulco to Zihuatanejo. Strikers blocked the highways of the town. In 1953, the town gained municipality status. In the 1970s, the area changed radically when the federal government decided to develop the Zihuatanejo-Ixtapa area into a tourist attraction. This caused the population to increase dramatically, especially in the 1980s and today the main economic base is tourism. Tourism in Zihuatanejo was negatively impacted by some events in the 2000s. In May 2008, bull sharks gathered in large numbers along the coast for unknown reasons; two surfers were killed and a third was injured. The attacks occurred during a three-week period causing a "Jaws-like mania" and the construction of lifeguard towers and the establishment of a shark patrol for the beaches of Zihuatanejo and north. It was