second major study was sponsored by the Louisiana Department of Transportation led by Ivor van Heerden at Louisiana State University. Studies were also done by FEMA, the insurance industry, the National Research Council, the National Institute of Standards and Technology, and the Katrina Consolidated Lawsuit. All studies basically agreed on the engineering mechanisms of failure. The primary mechanisms of failure at the 17th Street Canal, London Avenue Canal and Industrial Canal (east side north) were improper design of the canal floodwalls. The failure mechanism for the Industrial Canal (east side south and west side) was overtopping of levees and floodwalls by the storm surge. The primary mechanism of failure for levees protecting eastern New Orleans was the existence of sand in 10% of places instead of thick Louisiana clay. The primary mechanism of failure for the levees protecting St. Bernard Parish was overtopping due to negligent maintenance of the Mississippi River Gulf Outlet, a navigation channel, built and maintained by the Corps of Engineers. A June 2007 report by the American Society of Civil Engineers in peer review panel concluded that the flooding in the Lakeview neighborhood (from the 17th Street Canal) and the Gentilly neighborhood (from the London Avenue Canal) was due to two engineering oversights. The engineers responsible for the design of the canal levees and the I-walls embedded in them overestimated the soil strength, meaning that the soil strength used in the design calculations was greater than what actually existed under and near the levee during Hurricane Katrina. "The engineers made an unconservative (i.e., erring toward unsafe) interpretation of the data: the soil below the levee was actually weaker than that used in the I-wall design" (ASCE: External Review Panel, pg 48). Another critical engineering oversight that led to the failure of the 17th Street Canal involves not taking into account the possibility of a water-filled gap which turned out to be a very important aspect of the failures of the I-walls around New Orleans. “Analysis indicate that, with the presence of a water-filled gap, the factor of safety is about 30 percent lower. Because a factor of safety of 1.3 was used for design, a reduction of 30 percent would reduce the factor of safety to approximately one: a condition of incipient failure.” (ASCE: External Review Panel, pg 51) This meant that the design included a safety factor of 30% ("1.3"), and could cope in theory