Some 200 New Orleans school buses sit underwater in a parking lot, unused. That's enough to have evacuated at least 13,000 people. Why weren’t those buses sent street by street to pick up people before the storm?
A draft emergency plan, prepared by the Federal Emergency Management Agency and obtained by NBC News, calls for "400 buses to ... evacuate victims." Yet those 200 buses were left in Katrina's path.
"That's a real tragedy that these resources weren't employed," said Greg Shaw, a disaster management expert at George Washington University," because it would have been good to get those people out of the city."
Tuesday, the mayor of New Orleans would not comment.
On the federal level, clearly the arrival of the military has helped. But why did it take so long?
Last Wednesday, an Army officer said the nation's elite rapid deployment group, the 82nd Airborne, had 3,500 soldiers and 30 helicopters ready to be in New Orleans within hours. Yet they arrived only on Labor Day.
Tuesday, the Pentagon was defensive.
"Not only was there no delay," said Chairman of the Joint Chiefs of Staff Gen. Richard Myers, "I think we anticipated in most cases — not in all cases, but in most cases — the support that was required. And we were pushing support before we were formally asked for it."
A persistent unanswered question is, why didn’t the military just drop pallets of water to those stranded in various locations?
"This was an inexcusable failure of the government," said Gunnar J. Kuepper with the International Association of Emergency Managers.
One huge bottleneck in the evacuation — the New Orleans airport. Officials say flights were delayed while screeners and air marshals were flown in to comply with post-9/11 security requirements, and then further delayed because screening machines weren’t working. Finally, someone at Homeland Security signed an order to allow evacuees to be screened by hand.
So far, there are many more questions than official answers about the delays and failures on the state, local and federal levels that, critics say, made this catastrophe even worse.