Above are pictures of Unzen, in Japan.  After lying dormant for 198 years, it began erupting in 1990, and continued for four years.  Though there was little loss in life, there were over ten thousand ashflows counted during the eruption period.  During the eruption, a large lava dome built, but the eruption only garnered a VEI 3.  The picture below was taken after a pyroclastic flow swept into the town at the base of the volcano, killing 43 people.  Unzen is a 'decade volcano', that is, one that poses a serious threat to population centers.