During this period, the island was covered with an abundant forest that provided wood for the construction of housing, fishing boats, and tools. It also protected the fields from wind and the farmland from erosion. During the 17th century, around 1640, a long period of drought destroyed the already limited and probably over-exploited agricultural resources and forests of the island. In order to bring back the rain, the RapaNui, in a final attempt to call upon the help of their guardian ancestors, launched a frenetic phase of Moaïs sculpting. Each statue was more gigantic than the next. They are those found unfinished on the slope of the volcano. Their last effort was to no avail, and the rain did not return. The ensuing food shortage caused social tensions, and then came a period of famine, followed by civil wars and chaos. Cannibalism and slavery followed the previous period of peace. The contract linking the RapaNui to their ancestors was broken, and the cult of the Moaïs was abandoned. The statues, symbols of religious and political power, were torn down and broken.