Bush authorized aid on 8/27 (Saturday)
The difficult part to understand here is that while the Feds authorized aid on 8/27 (the Saturday before the hurricane), what took LA so long to request it? Before someone says the Feds should have rushed in, there are laws preventing just that from happening and the Washington Post reports that as of Friday night that Blanco is still fighting the Feds from taking a more active/coordinating role in disaster relief.