Actually, the first levee broke about 2 hours after Katrina made landfall. ABC News first reported a levee broke about 3 hours later.oldunion said:Or the levee was blown to make it look like it was a result of the hurricane. Remember it broke the day after, not the day the hurricane hit.
Unfortunately, communications was horrible. One of the side effects of the US's extensive cell phone and land line communication networks is satellite phones have never really taken off in the US (remember what happened to Iridium). Combined, the National Guard had one satellite phone for entire Gulf Coast (the Middle East relies much more on satellites for phone service, so virtually all of the National Guard's satellite phones were sent to Iraq). With land communication lines wiped out, there wasn't much in the way of communication. With no one in charge saying anything about the levee system, the story got dropped as rumor.
Even the Army Corps of Engineer's top official in New Orleans (Col Wagenaar) seemed unaware of the extent of damage to the levee system. Someone from the New Orleans police department had managed to tell the ACE about the levee break, but the ACE couldn't get anyone to the site to check it out. That evening, Wagenaar was the official who said, "The fact that Katrina didn't cause more damage is a testament to the structural integrity of the hurricane levee protection system."
The Washington Post has a good article on the buildup to the hurricane and immediately after the hurricane.