Chaitén is a volcanic caldera 3 kilometres in diameter, 10 kilometres northeast of the town of Chaitén. The volcano entered a new eruptive phase for the first time in about 9,500 years on the morning of May 2, 2008. Forests near the volcano have been burned by pyroclastic flows and lateral explosions. Lahars caused flooding in the town of Chaitén, depositing ash mud to a depth of up to a metre or more, damaging many buildings, and completely filling the original course of the Chaitén River past the town.