What exactly happened nine months ago when New Orleans' levees and flood walls were overwhelmed by Hurricane Katrina?
A document being released today may have some answers.
The widely anticipated report from the Army Corps of Engineers contains more than six-thousand pages and is expected to include details on alleged engineering and design failures.
A Corps spokesman calls the report "a milestone." But it's not expected to criticize the organizational mind-set of the Corps.
A report last month by an outside team of engineers said the Corps was dysfunctional and undependable. It recommended setting up an agency to oversee the Corps' projects nationwide.
The Corps says New Orleans' flood defenses are better now than before Katrina.