The US Army Corps of Engineers knew about "engineering mistakes" that led to levee failures in New Orleans 15 years before Hurrican Katrina let to levee breaches.
But the Corps decided not to act on the findings.
The Times-Picayune got hold of the documents. They turned them over to forensic engineers studying the levee breaches.
The engineers say the documents show project engineers made a critical mistake in assessing soil strengths on the 17th Avenue Canal project.
Robert Bea is a University of California-Berkeley professor who is a member of the National Science Foundation team who looked at the documents.
He says after the Corps found the mistake, the documents indicate they decided to ignore the problem -- and no one ever raised the issue again.