Here's the first true thing that came to mind when the plane crashed into the building. It was a comic strip that appeared in my local newspaper 5 years ago, I think. Here's how it goes,
"They though of every single possible security measure possible but...."
and then a picture of a plane that had crashed into a skyscraper.
I know it's a sad thing to say.
I honestly do feel sorry for victims, but like Jari said earlier, I don't think this is an unexpected thing. Obviously this isn't happening without reason, something else bigger might follow this "event". I know it isn't right to claim the lives of innocent people, but I have a feeling that these people aren't only doing this for attention...