How should Bush repond to Mccain's calling katrina the worst diaster handling in modern History?

Sen.Mccain is hitting hard on President Bush about Katrina. How should he handle it? Should he ignore or say Mccain is out of line.

Acknowledge that mistakes were made and he failed, but he will say nothing as to help Mccain. This has already been worked out since his approval ratings are the lowest in decades of all the Presidents. Bush will be silent until the election is over and if Mccain loses, he will laugh because he knows Mccain does not like him!

Bush should respond by apologizing for how badly he handled the whole situation.
The top weather forecaster and hurricane expert in the US, I forgot his name, said he had a meeting with Bush where he explained to Bush for an entire hour what was going to happen in New Orleans.
According to the expert at the end of the hour Bush got up and left the room without asking a single question.
McCain is honest enough to see clearly how Bush blundered so badly in this matter.

It doesn't really matter how Bush responds. It is over and done. I think most people do believe that the handling of Katrina was a mess regardless of how Bush responds. McCain is just reflecting on public sentiment - not saying anything so out of step with what most people believe to be true anyway. It is a political move by McCain and Bush should understand that. No one ever wants to think that this could happen again, and McCain is seizing the opportunity to reassure people that the terrible response like that of Katrina to a natural disaster will never again happen if he is elected President. I honestly don't know how he can promise that unless he is a psychic; but I do know that Bush should just let it go if he is interested in helping a Republican to be the next President. If Bush gets involved, it will just look like in-fighting by spoiled, little kids.