When a failure occurs, geotechnical engineers, engineering geologists, and geophysicists assign its cause to an event that immediately precedes the failure, such as an earthquake, heavy rainfall, flood, or other natural event. Assigning the failure to the immediate event is misplaced; the metastasis occurred because marginally stable conditions were allowed to exist through substandard investigations by the technical personnel, improper design, and inadequate review by the permitting agency. The fundamental cause of the failure is human error and is manifested in one or more of six categories. (1) Before the investigation, during discussions with the client. (2) During the investigation, by collecting inadequate, incomplete, or incorrect data; altering the field or test data to make them more favorable. (3) After the investigation, when the inadequate data and invalid conclusions are incorporated in the final report. (4) During the review process, when the reviewers accept the substandard report. (5) After the agency approves the substandard report. (6) After the agency grants the permit that allows construction to begin and after the work begins. Eleven case studies of failures are described including landslides, dam failures, floods, and ground subsidence. Each case study identifies (1) the immediate event, (2) the fundamental cause, (3) how the inadequacies and deficiencies in one or more of the six categories contributed to the failure, and (4) how the failure could have been prevented. Each of these failures resulted in civil or criminal court action. Depending on the facts in each case, penalties were imposed on the engineer, geologist, or geophysicist
