WSJ probably has a good handle on what the witnesses say, but they're missing a couple of significant components.
1. The sat imagery in this thread:
http://www.freerepublic.com/focus/f-news/1484919/posts
...show that east Orleans (east of the Industrial Canal) probably did not flood from topped levees in the Canal, and also indicate a significant surge was funneled west along the Intercoastal Waterway, part of which continued west, topping the western Canal levees and flooding a significant portion of northeastern downtown (corroborated by early news reports, but not later ones, as you;d expect from a short lived surge event topping levees but not breaching them),
...and the other part of which flowed south down the Canal, tearing the barge loose and putting it through the concrete wall. From the pictures, the barge currently sits southeast of the breach, indicating both its southerly and easterly velocity component when it breached the wall.
However, this does not explain two separate issues. One, why the entire area flooded so quickly (a quick over view of the area indicates the disparity in size between the Industrial Canal and the flooded areas of the Ninth Ward and St.Bernard's Parish, and two, the oft posted images showing water flowing OUT of St. Bernard into the canal, along with reports that this area filled so high that "we can't see the tops of the levees any more".
This thread:
http://www.freerepublic.com/focus/f-news/1484668/posts
...indicates significant subsidence affected the levees on the northeastern edges of St. Bernards Parish, lowering what were supposed to be 17 foot levees to in some cases as low as 6.6 feet above sea level, as far back as 1999.
Per the WSJ article posted in this thread and others, officials are now trying to claim that Katrina washed away those low levee sections, through others as noted in the article above, admit that subsidence played a part years before the storm arrived.
Still looking for the failure mechanism for the 17th street canal, and the mechanism which allowed east Orleans Parish to flood.
Early assessments indicate that the 17th street levee was probably topped, based on a 0345 Monday report from Kenner that the canal NW of there (with walls the same height as the 17th street Canal) was full at that time.
Early assessments also indicate that east Orleans probably flooded from a heightened surge funneled between the seawalls north of St. Bernard's and south of east Orleans, but I also believe that there probably was a breach somewhere out that way because of the manner in which east Orleans flooded, early and full.
In any event, I'd like like to firm these two suppositions up, so if anyone comes across engineering or other reports that bear on the issues, a ping would be appreciated.
Good additional information----thanks. I'm sure that this will all be accounted for in the "final" Corps of Engineers report. The Corp has some pretty damned good staff engineers and scientists up at Vicksburg.
"...indicates significant subsidence affected the levees on the northeastern edges of St. Bernards Parish, lowering what were supposed to be 17 foot levees to in some cases as low as 6.6 feet above sea level, as far back as 1999."
Yeah, I saw that thread. Someone needs to ask some VERY POINTED QUESTIONS of the St. Bernard Parish Levee Board.