Dome collapses at Montserrat

Wow, this took a really long time to develop. This is what happens at the end of a long eruption, such as the disaster of Pompeii. When it hits, the whole area gets swept with hot, nasty volcanic gas flows. With Vesuvius it happened fairly quickly, about a month is normal. With Chaiten, it still hasn't happened yet, and that volcano is one heck of an energizer bunny!