Sample pilings pulled up were found to be of the length specified in the design ( 17 feet ) .
It was then revealed that this length was less than the actual depth of the canal , in retrospect an obvious engineering mistake .
Sample pilings pulled up were found to be of the length specified in the design ( 17 feet ) , but it was then revealed that this length was less than the actual depth of the canal , in retrospect an obvious engineering mistake .