According to this report, posted at 6:31 AM EDT, there are breaks in at least 3 levees:
http://ap.wwltv.com/dynamic/stories/H/HURRICANE_KATRINA?SITE=WWL&SECTION=HOME&TEMPLATE=USHEADS.html&CTIME=2005-08-29-18-59-09
"Even with Katrina swirling away to the north, two different levee breaches in New Orleans sent a churning sea of water coursing through city streets."
"Col. Rich Wagenaar of the Army Corps of Engineers, said a breach in the eastern part of the city was causing flooding and "significant evacuations" in Orleans and St. Bernard parishes. He did not know how many people were affected by the flooding."
"Authorities also were gathering information on a levee breach in the western part of New Orleans. Jason Binet, of the Army Corps of Engineers, said that breach began Monday afternoon and may have grown overnight."
"In a particularly low-lying neighborhood on the south shore of Louisiana's Lake Pontchartrain, a levee along a canal gave way and forced dozens of residents to flee or scramble to the roofs when water rose to their gutters."
A little while ago, I saw a reporter on TV updating the status of conditions in the French Quarter. The cameras panned the area showing the beginnings of flooding. Not good.