A litle error has huge consequences. According the Times Picayune:
A difference in soil-boring data transferred from one chart to another may have played a key role in engineering decisions that led to the breach on the 17th Street Canal floodwall during Hurricane Katrina, National Science Foundation investigators say.We all make mistakes, but doesn't anyone at these engineering firms check the work of another, especially when failures can be deadly.
A cross-section drawing in the project design documents shows a weak layer of peaty soils between 11 feet and 16 feet below sea level in the area that failed during the storm. But information in the individual soil borings that were used to draw the cross section show the peaty layer extending as deep as 30 feet below sea level.
Investigators also have been puzzled by what they say are obvious engineering errors because the firms involved -- Eustis Engineering for the soil profiles, Modjeski and Masters for the general design -- were experienced and reputable in their fields. Work by the National Science Foundation team, however, may have uncovered a small mistake that had a huge impact.