I too find Michael Chertoff's denial of any knowledge of conditions in the Superdome very unconvincing. Everyone else in America knew it, what world is he living in? It's particularly off-putting when he sat there and denied any knowledge to Chris Wallace as though he were denying that he knew about an unpaid parking ticket. I think if the DHS truly did not have that information (very doubtful), it must be because they didn't want it. As it was, he came across at best as a bloodless bureaucrat who was covering his arse.
None of this excuses the Major or the Governor in any way, they are culpable of homicidal bungling and worse. That doesn't change the fact that the Dir of Homeland Security looks to be sidestepping any responsibility for action in a national disaster and it makes the whole administration look bad.
It was the Convention Center he did not have knowledge about.
Nobody learned that people had on their own gone to the Convention Center until Thursday, far as I can tell. Some report they broke in, some report the police opened it up for them, but it was never a designated shelter of last resort or an official staging area for evacuees.