Delve a little deeper into volcanic hazards

In the textbook reading and PPTs this week, you learned a great deal about how volcanoes work and what many of the hazards to human life and property are.   Since one of my favorite things about geology is death and destruction, for this weeks discussion I would like everybody to delve a little deeper into volcanic hazards.  I would like everybody to pick 1 type of volcanic hazard that was discussed in the reading or PPT, and find a historical example of that hazard and recount it to the class.  There are many really cool examples to choose from such as lava flows, pyroclastic flows, tsunamis caused by volcanoes, mud flows, poisonous gas, oooohh, what fun!

You must include your references.  You may NOT plagiarize.  Its very easy to tell when you do, trust me.  Again, this has the potential to be a very cool assignment, so get into it and enjoy it!