Mount Pinatubo

  Mount Pinatubo is an active volcano located on the island of Luzon in
  the Philippines, at the intersection of the borders of the provinces
  of Zambales, Bataan, and Pampanga.  Before 1991, the mountain was
  inconspicuous and heavily eroded.  It was covered in dense forest which
  supported a population of several thousand indigenous people, the
  Aeta, who had fled to the mountains from the lowlands when the Spanish
  conquered the Philippines in 1565.  The volcano's most recent eruption
  in June 1991 came after 500 years of dormancy, and produced one of the
  largest and most violent eruptions of the 20th century.  Successful
  predictions of the onset of the climactic eruption led to the
  evacuation of tens of thousands of people from the surrounding areas,
  saving many lives, but the surrounding areas were severely damaged by
  pyroclastic flows, ash deposits, and later, lahars caused by rainwater
  remobilising earlier volcanic deposits, and thousands of houses were
  destroyed.  The effects of the eruption were felt world-wide.  It
  injected large amounts of aerosols into the stratosphere—more than any
  eruption since that of Krakatoa in 1883.  Global temperatures dropped
  by about 0.5 °C (0.9 °F), and ozone destruction increased
  substantially.

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  http://en.wikipedia.org/wiki/Mount_Pinatubo