I don't think the two are really comparable. Both caused suffering. Each is the worst to the people who it effected directly. Those who lost loved ones probably don't even think about the tragedies in the same way as those of us who watched it on the news and read about it in newspapers.

This!

9/11, on ccount of the fact that it convinced our fearless leader to destroy America.

why would you ask that question? It doesn't matter which was worse,they were both sad and tragic.

Well, I put Katrina, based on the initial damage it did. Even though some say 9/11 caused the war, I am of the mindset that the whole entire thing was destined to happen anyways.

I will say though, it was still a hard decision. I have a really really hard time feeling sorry for people that live in a area prone to be hit by hurricanes that is below sea level. But clearly I still feel bad for them, I did pick it :

The Norway disaster, oh wait...

Katrina was. 9/11 was a horrible ordeal but it was the actions after the events by the Bush administration that turned it into the terrible mess that it is today.