A multidisciplinary, automobile crash investigation team at the Jackson Memorial Hospital/Ryder Trauma Center in Miami, Florida, is conducting a detailed medical and engineering study. The focus is restrained (seatbelts and/or air bag) occupants involved in frontal crashes, who have also been severely injured. More than 60 crashes have been included in the study to date.Analysis of the initial data indicates that restraint systems are working to reduce many of the head and chest injuries which unrestrained occupants suffer.However, internal injuries among air bag-protected occupants may be unrecognized in the field providing new challenges in triage and injury diagnosis. In other cases, survival in extremely high severity crashes presents trauma management challenges due to the extent and complexity of the multiple injuries which result. The paper provides case examples to illustrate types of chest and abdominal injuries associated with air bag cases. Three types of cases are presented: (1) Jackson Study Involving Occult Chest/Abdominal Injury, (2) National Accident Sampling System (NASS) Special Crash Investigation (SCI) and (3) Jackson Study Involving Crash Severities Greater than 45 MPH.To assist in recognizing the extent of injuries to occupants protected by air bags, it is suggested that additional evidence from the crash scene be used in the triage criteria. For the occult chest/abdominal cases observed in the Jackson study, deformation of the steering system was the vehicle characteristic most frequently observed.The challenges of recognizing injuries to air bag-protected occupants are discussed. The presence of steering wheel deformation may be a sufficient signal of caution to justify transporting the injured victim to a Level 1 or 2 trauma center so that a close examination for occult injuries can be made.