One of five special economic zones (SEZ), sun-blessed Hainan province has long had a reputation for rebelling against the central government and for lawlessness. Hainan in the late 1980s and early 1990s was characterised by a roaring economy based on smuggling, the sex trade and, above all, property speculation, which helped to fuel corruption. In 1988, the former mayor of Shenzhen, Liang Xiang, became the province's first governor, only to be sacked the following year for corruption. In 1993, four senior managers of state-owned enterprises in Hainan were executed for the misappropriation of 26 million yuan (HK$24.1 million), which was the mainland's biggest corruption case until then. Although Hainan is well known as the least polluted province in China, and its warmest, the development of its tourism industry had been ignored by provincial leaders until its deep economic malaise a decade ago forced a radical rethinking of the economic potential. The tropical island, which sits along the same latitude as Hawaii, was part of Guangdong province until 1988, when it was granted provincial status and became an SEZ. Late paramount leader Deng Xiaoping toured the island in 1992, sparking a bubble economy - most of it in property - that lasted for two years. But with the launch of the mainland's austerity programme in 1994, Hainan's bubble burst as credit became more and more scarce. In the span of a few months, the value of real estate on the island fell by more than 30 per cent, littering Haikou, its main city, with empty office towers, luxury housing developments and under-used hotels and resorts. In 2001, the lingering economic downturn helped trigger the collapse of Hainan International Trust and Investment Corp after the ailing state enterprise defaulted on its bonds. In the spring of that year, Hainan province again made international headlines when a PLA jet fighter collided with a US spy plane, forcing the US aircraft to make an emergency landing on the island.