Ugh -- while I agree with Smiling Joe that he died doing what he loved to do, and he lived life to the fullest, I sure feel bad for those kids.

However I think they will be OK. I'm sure they have a ton of support and their dad will loom nearly as large as he did while he was alive.
My 6 yo went through a Crocodile Hunter phase last year and actually emailed Steve Irwin to tell him how much he liked him. We got a response from the Australia Zoo and they sent him a "fun pack" with stickers, information on animals and a pic of the family. He doesn't watch the show much at all now so I don't think I will tell him about this. But it is incredibly sad. Such a freak accident.