Watching the Twin Towers and the Pentagon on 9/11 and watching the Challenger erupt are the two that seared themselves into my brain as the worst. I think watching Wlater Cronkite cry when he announced Kennedy was dead may have been the most disquieting. Hugo, Katrina and the Northridge earthquake rank up there in the "natural" disaster ranks.
Whoa, what a dreary thread...

A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)