25 Oct 1999 h. 13:01. This video lasts 51 s, i.e. 2.6 MB, but it's really worthwhile to download it all :-). The activity at NWV is now very intense. As long as the spatter falls back into the crater, everything proceeds smoothly, but as soon as some bombs manage to impact on the external flank, now completely unstable, a collapse much bigger than all the previous ones is started. The blocks fragment and multiply the size of the landslide, that soon, also probably thanks to the high temperature, transforms into a real pyroclastic flow, obviously on a much smaller scale if compared to e.g. Unzen or Montserrat. However, the flow is spectacular and it ends, according to theory, with the deposit of the heavier material and the upraising of the lighter remaining particles, which form a column that is in turn pushed backwards by the wind, again towards Bocca Nuova.