I was considering voting 'tsunami' first, but then decided to go with '911'. As previous posters have stated, the tsunami was a natural event. Earthquakes and tsunamis are a fact of life here on Earth. They happen all the time, and the impact they have on us is the consequence of living on a volatile planet. The tsunami in Asia isn't a rare event, they happen all the time. 9/11, on the other hand, was planned and carried out by terrorists seeking to destroy a specific people. Just the amount of thought and scheming terrorists did to attack the US was enough for me to pick '911'. The death toll of the tsunami is caused by a natural disaster, disease and lack of water. The death toll of 9/11 was the result of suicidal terrorists hijacking gas loaded jets. While the death toll was obviously much smaller in 9/11, the psychological impact and how it frightened hundreds of millions of people in the world to see terrorists lash out so violently made it a "worse" event in my book, but of course 9/11 and the recent tsunami aren't directly comparable in every way.. Just my .02.