A new study by the National Institute of Standards and Technology (NIST) shows scientifically for the first time that an individual’s ability to respond quickly to a residential fire determines who dies and who gets injured. Home fire deaths, the NIST researchers state, are more likely among those they define as frail populations—persons who are not in robust health and primarily age 65 and older—while nonfatal injuries occur more often in adults ages 20 to 49.The findings suggest that vulnerability to fires in homes could be mapped for communities across the United States based on age demographics, and in turn, measures designed to prevent fire deaths and injuries could be targeted to the appropriate populations to maximize their effectiveness.