I absolutely think you should talk to your students about tragedies- personal or worldwide. If a student or students are facing a tragedy it will most likely affect their behaior and work ethic in the classroom. I also believe that if you bottle up your emotions it only makes them worse. You can locate resources to help you and your students by going to http://www.nasponline.org/NEAT/crisis_0911.html. To help students learn from the tragedy of hurricane Katrina you could set up donations to help the victims. You could share some of the victims stories and ask them how they could relate it to their own life or simply how they feel about it. I would turn this in to a teachable moment. We could have a class that teaches about hurricanes. What are they? Where do they come from? You should be sensitive to the children’s feelings and emotions. If I were teaching a first grade classroom I wouldn’t show newsclips. You want them to be aware but you don’t want to scare the crap out of them where they think they are going to die.