"By midnight on Monday the White House knew. Monday night I was at the state Emergency Operations Center and nobody was aware that the levees had breeched. Nobody."

The charges were so devastating - the White House's withholding from the state police the information that the city was about to flood - that from almost any source, I simply would have dismissed it. But this was not just any source. The whistleblower was Dr. Ivor van Heerden, deputy chief of the Louisiana State University Hurricane Studies Center, and the chief technician advising the state on saving lives during Katrina.

That Monday night, August 29, 2005, the sleepless crew at the state Emergency Operations Center, directing the response to Hurricane Katrina, were high-fiving it, relieved that Katrina had swung east of New Orleans, sparing the city from drowning.

They were wrong. The Army Corps, FEMA and White House knew for critical hours that the levees had begun to crack, but withheld the information for a day and night. The delay was deadly.

Van Heerden explained that levees don't collapse in a single bang. First, there's a small crack or two, a few feet wide, which take hours to burst open into visible floodways.

Had the state known New Orleans' bulwark was failing, they would have shifted resources to get out those left in the danger zone.