Fatalities in the United States Indirectly Associated with Atlantic Tropical Cyclones

A review of storm-related reports and databases for 59 U.S. tropical cyclones from the past half-century tells us that the number of indirect deaths is almost as large as the number of direct deaths. Indirect deaths occurred most often in association with loss of electricity, cardiovascular failure, evacuation, and vehicle accidents. The prestorm phase presented significant threats to safety mainly from accidents during home preparations (e.g., fall from a ladder or building) and in association with evacuations, mainly from vehicle accidents and/or incidents involving the elderly. Most indirect fatalities, however, occurred after a triggering storm condition or after the storm had completely passed. The loss of electricity was noted in many of those cases. It was the antecedent to falls in the dark and/or down stairs, house fires, inoperative life-sustaining medical equipment, CO poisoning, hypothermia, electrocution during power restoration or from power lines that were unexpectedly live, and vehicle accidents associated with inoperative traffic lights. The importance of electricity is likely greater than indicated because the available data exclude the count of those who evacuated at least partly out of concern that power would be lost, and then died during the evacuation process (e.g., the Hurricane Rita bus tragedy) or at their evacuation destination. It also doesn't include some who died from the exacerbating impacts of heat stress resulting from a sometimes-extended period without air conditioning. Other incidents noted most often in the latter stages of the storm or after the storm's passage were recovery activities, vehicle accidents on slippery roads, and vehicle collisions with downed trees. We highlight further the involvement of trees in fatal incidents as, like loss of electricity, they appear in multiple types of fatalities. In addition to posing a deadly roadway obstacle, they were noted in storm clean-up accidents and heart attacks, some from physical overexertion. We recall that Rappaport (2000) noted toppling and fracturing trees were also causes of direct deaths. Cardiovascular failures occurred with especially great frequency, in about one-third of the indirect deaths. Evacuating and being evacuated also accounted for a significant number of indirect deaths. This observation supports the practice of care providers comparing the relative risk of conducting an evacuation - especially of the frail and elderly - to the risk of not evacuating. The data make clear that reducing the number of deaths associated with tropical cyclones in a significant way will require decreasing the occurrences of both indirect and direct deaths. Improvements in the hurricane forecast enterprise have led to a decrease in the number of direct deaths from what would have been expected otherwise (Willoughby et al. 2007). Among those life-saving advances over the study period has been a lengthening of the tropical cyclone forecast horizon from two days to five days. Paradoxically, the increase in lead time also provides opportunity for an increase in certain kinds of casualties, most notably indirect casualties during the lengthened preparation phase. It should then not be surprising that while the ratio of direct deaths to indirect deaths was more than two to one up through 1995, the ratio has reversed since approximately 2000 - though changes in reporting procedures (i.e., recognizing and providing more information explicitly about indirect deaths) are likely also partly responsible for the change. Minimizing indirect deaths will require focused outreach and education. We hope this study has identified the risks that can form the focus of those efforts to provide for greater public safety and the impetus to make significant progress quickly. ©2016 American Meteorological Society.