An in-depth understanding of human factors and human error is lacking in current research on seniors' falls. Additional knowledge is needed to understand why seniors are falling. The purpose of this article is to describe the adapting of the Integrated Safety Investigation Methodology (ISIM) (used for investigating transportation and industrial accidents) to studying seniors' falls. An adapted version—the Seniors Falls Investigative Methodology (SFIM)—uses a systems approach to take an investigation beyond the immediate cause of an incident and reveal unsafe acts and deeply imbedded unsafe conditions that contribute to adverse outcomes. An example case study is used to describe six phases of the investigative process in detail. The SFIM has the potential to identify safety deficiencies; utilize existing knowledge about falls; establish a standardized reporting system; shift focus from the faller to the system; and guide targeted prevention.